diff --git a/backend/src/module/api/rss.py b/backend/src/module/api/rss.py
index d4362e6c..5f930b3c 100644
--- a/backend/src/module/api/rss.py
+++ b/backend/src/module/api/rss.py
@@ -13,6 +13,10 @@ from .response import u_response
 
 router = APIRouter(prefix="/rss", tags=["rss"])
 
+# RSSItem.parser 的合法取值（与 webui ab-add-rss 的选项一致）；
+# 这些值即便与搜索站点同名（mikan）也不做站点名映射
+PARSER_TYPES = {"mikan", "tmdb", "parser"}
+
 
 @router.get(
     path="", response_model=list[RSSItem], dependencies=[Depends(get_current_user)]
@@ -205,10 +209,14 @@ async def download_collection(data: Bangumi):
     "/subscribe", response_model=APIResponse, dependencies=[Depends(get_current_user)]
 )
 async def subscribe(data: Bangumi, rss: RSSItem):
-    # 搜索订阅时前端传来的是站点名（nyaa/dmhy/mikan），而分析器只认识解析器
-    # 类型 mikan/tmdb（见 rss/analyser.py），站点名会静默跳过 TMDB 补全（#1053）。
-    # 这里按搜索源配置把站点名映射为解析器；已是解析器类型的值原样透传。
-    providers = get_provider()
-    parser = providers[rss.parser]["parser"] if rss.parser in providers else rss.parser
+    # 搜索订阅时前端传来的是站点名（nyaa/dmhy），而分析器只认识解析器类型
+    # mikan/tmdb（见 rss/analyser.py），站点名会静默跳过 TMDB 补全（#1053）。
+    # 这里按搜索源配置把站点名映射为解析器；已是解析器类型的值原样透传，
+    # 且不参与站点映射——避免 "mikan" 这类与站点同名的解析器被配置改写。
+    parser = rss.parser
+    if parser not in PARSER_TYPES:
+        providers = get_provider()
+        if parser in providers:
+            parser = providers[parser]["parser"]
     resp = await SeasonCollector.subscribe_season(data, parser=parser)
     return u_response(resp)
diff --git a/backend/src/module/database/rss.py b/backend/src/module/database/rss.py
index 0f68923d..cc345b24 100644
--- a/backend/src/module/database/rss.py
+++ b/backend/src/module/database/rss.py
@@ -94,9 +94,11 @@ class RSSDatabase:
         return await self.session.get(RSSItem, _id)
 
     async def search_url(self, url: str) -> RSSItem | None:
+        # url 仅有索引而无唯一约束（去重只在 add() 里做），遗留库可能存在
+        # 重复行，用 first() 而非 scalar_one_or_none() 以免抛 MultipleResultsFound
         statement = select(RSSItem).where(RSSItem.url == url)
         result = await self.session.execute(statement)
-        return result.scalar_one_or_none()
+        return result.scalars().first()
 
     async def search_all(self) -> list[RSSItem]:
         result = await self.session.execute(select(RSSItem))
diff --git a/backend/src/module/manager/torrent.py b/backend/src/module/manager/torrent.py
index 226c2082..e5aa166c 100644
--- a/backend/src/module/manager/torrent.py
+++ b/backend/src/module/manager/torrent.py
@@ -52,11 +52,13 @@ class TorrentManager:
                 msg_zh=f"无法找到 {data.official_title} 的种子",
             )
 
-    async def _delete_orphan_sub_rss(self, data: Bangumi) -> None:
-        """删除该番剧独立订阅（aggregate=False）且不再被引用的 RSS 条目（#1053）。
+    async def _disable_orphan_sub_rss(self, data: Bangumi) -> None:
+        """停用该番剧独立订阅（aggregate=False）且不再被引用的 RSS 条目（#1053）。
 
-        聚合订阅由多个番剧共享，永不在此处删除；rss_link 可能是逗号拼接的
-        多个链接（见 BangumiDatabase.match_list），逐个拆分精确匹配。
+        停用而非删除：无法区分搜索订阅与用户手动添加的独立订阅，删除还会
+        连带清掉该 rss_id 下可能属于其他番剧的种子去重记录。聚合订阅由多个
+        番剧共享，永不在此处停用；rss_link 可能是逗号拼接的多个链接
+        （见 BangumiDatabase.match_list），逐个拆分精确匹配。
         """
         urls = {u.strip() for u in (data.rss_link or "").split(",") if u.strip()}
         if not urls:
@@ -67,11 +69,14 @@ class TorrentManager:
             still_referenced.update(
                 u.strip() for u in (bangumi.rss_link or "").split(",") if u.strip()
             )
+        orphan_ids: list[int] = []
         for url in urls - still_referenced:
             rss_item = await self.db.rss.search_url(url)
-            if rss_item and not rss_item.aggregate:
-                await self.db.rss.delete(rss_item.id)
-                logger.info(f"[Manager] Delete orphan RSS feed {url}")
+            if rss_item and not rss_item.aggregate and rss_item.enabled:
+                orphan_ids.append(rss_item.id)
+                logger.info(f"[Manager] Disable orphan RSS feed {url}")
+        if orphan_ids:
+            await self.db.rss.disable_batch(orphan_ids)
 
     async def delete_rule(self, _id: int | str, file: bool = False):
         data = await self.db.bangumi.search_id(int(_id))
@@ -79,8 +84,8 @@ class TorrentManager:
             # Clean up torrent records so re-adding the same anime can re-download
             await self.db.torrent.delete_by_bangumi_id(int(_id))
             await self.db.bangumi.delete_one(int(_id))
-            # 番剧删除后清理其独立订阅的孤儿 RSS；聚合订阅不受影响
-            await self._delete_orphan_sub_rss(data)
+            # 番剧删除后停用其独立订阅的孤儿 RSS；聚合订阅不受影响
+            await self._disable_orphan_sub_rss(data)
             torrent_message = None
             if file:
                 # Only the file-cleanup path needs the downloader, so an
diff --git a/backend/src/module/network/request_url.py b/backend/src/module/network/request_url.py
index e478c167..85983060 100644
--- a/backend/src/module/network/request_url.py
+++ b/backend/src/module/network/request_url.py
@@ -1,5 +1,6 @@
 import asyncio
 import logging
+import math
 from typing import Any
 
 import httpx
@@ -33,9 +34,13 @@ def _retry_after_delay(response: httpx.Response) -> float:
     retry_after = response.headers.get("Retry-After")
     if retry_after is not None:
         try:
-            return min(max(float(retry_after), 0.0), HTTP_429_MAX_RETRY_AFTER)
+            value = float(retry_after)
         except ValueError:
-            pass
+            return HTTP_429_FALLBACK_DELAY
+        # float("nan") 能通过解析，且 min/max 会传播 NaN → asyncio.sleep(nan) 永不唤醒
+        if math.isnan(value):
+            return HTTP_429_FALLBACK_DELAY
+        return min(max(value, 0.0), HTTP_429_MAX_RETRY_AFTER)
     return HTTP_429_FALLBACK_DELAY
 
 
diff --git a/backend/src/test/test_api_rss.py b/backend/src/test/test_api_rss.py
index 258be53c..cdf8206c 100644
--- a/backend/src/test/test_api_rss.py
+++ b/backend/src/test/test_api_rss.py
@@ -419,3 +419,35 @@ class TestSubscribe:
         assert response.status_code == 200
         assert mock_subscribe.await_args is not None
         assert mock_subscribe.await_args.kwargs["parser"] == "tmdb"
+
+    def test_subscribe_known_parser_type_never_remapped(self, authed_client):
+        """parser='mikan' 是解析器类型而非站点名，即便用户自定义了 mikan
+        站点的解析器（如 tmdb），也不应被站点映射改写。"""
+        customized = {
+            "mikan": {
+                "url": "https://mikanani.me/RSS/Search?searchstr=%s",
+                "parser": "tmdb",
+            },
+        }
+        resp_model = ResponseModel(
+            status=True, status_code=200, msg_en="Subscribed.", msg_zh="订阅成功。"
+        )
+        with (
+            patch(
+                "module.api.rss.SeasonCollector.subscribe_season",
+                new_callable=AsyncMock,
+                return_value=resp_model,
+            ) as mock_subscribe,
+            patch("module.api.rss.get_provider", return_value=customized),
+        ):
+            response = authed_client.post(
+                "/api/v1/rss/subscribe",
+                json={
+                    "data": make_bangumi(id=1).model_dump(),
+                    "rss": {"url": "https://mikanani.me/RSS/link", "parser": "mikan"},
+                },
+            )
+
+        assert response.status_code == 200
+        assert mock_subscribe.await_args is not None
+        assert mock_subscribe.await_args.kwargs["parser"] == "mikan"
diff --git a/backend/src/test/test_database.py b/backend/src/test/test_database.py
index 3e34eaae..f2cc57dd 100644
--- a/backend/src/test/test_database.py
+++ b/backend/src/test/test_database.py
@@ -1037,6 +1037,20 @@ class TestRSSSearchUrl:
         rss_db = RSSDatabase(db_session)
         assert await rss_db.search_url("https://example.com/absent") is None
 
+    async def test_search_url_duplicate_urls_returns_one_without_raising(
+        self, db_session
+    ):
+        """URL 无数据库唯一约束，遗留库可能有重复行；不应抛 MultipleResultsFound。"""
+        url = "https://mikanani.me/RSS/dup"
+        db_session.add(RSSItem(url=url, name="A"))
+        db_session.add(RSSItem(url=url, name="B"))
+        await db_session.commit()
+
+        rss_db = RSSDatabase(db_session)
+        found = await rss_db.search_url(url)
+        assert found is not None
+        assert found.url == url
+
 
 class TestOrphanTorrents:
     """Tests for TorrentDatabase orphan-torrent operations (bangumi_id IS NULL)."""
diff --git a/backend/src/test/test_manager_torrent.py b/backend/src/test/test_manager_torrent.py
index d37d686d..72de0e6b 100644
--- a/backend/src/test/test_manager_torrent.py
+++ b/backend/src/test/test_manager_torrent.py
@@ -1,7 +1,8 @@
 """Tests for TorrentManager.delete_rule RSS cleanup (#1053).
 
-删除番剧时应一并清理其独立订阅（aggregate=False）的孤儿 RSS 条目；
-聚合订阅与仍被其他番剧引用的订阅不受影响。
+删除番剧时应停用其独立订阅（aggregate=False）的孤儿 RSS 条目（停用而非删除：
+无法区分搜索订阅与用户手动添加的独立订阅，删除会连带清掉其他番剧的种子
+去重记录）；聚合订阅与仍被其他番剧引用的订阅不受影响。
 """
 
 from module.database import Database
@@ -19,7 +20,7 @@ async def _seed(db: Database, *, bangumi=(), rss=()):
 
 
 class TestDeleteRuleRSSCleanup:
-    async def test_delete_rule_removes_orphan_sub_rss(self, db_engine):
+    async def test_delete_rule_disables_orphan_sub_rss(self, db_engine):
         async with Database(engine=db_engine) as db:
             await _seed(
                 db,
@@ -31,9 +32,11 @@ class TestDeleteRuleRSSCleanup:
             resp = await manager.delete_rule(1, file=False)
 
             assert resp.status is True
-            assert await db.rss.search_url(SUB_URL) is None
+            rss_item = await db.rss.search_url(SUB_URL)
+            assert rss_item is not None
+            assert rss_item.enabled is False
 
-    async def test_delete_rule_keeps_aggregate_rss(self, db_engine):
+    async def test_delete_rule_keeps_aggregate_rss_enabled(self, db_engine):
         async with Database(engine=db_engine) as db:
             await _seed(
                 db,
@@ -44,7 +47,9 @@ class TestDeleteRuleRSSCleanup:
 
             await manager.delete_rule(1, file=False)
 
-            assert await db.rss.search_url(SUB_URL) is not None
+            rss_item = await db.rss.search_url(SUB_URL)
+            assert rss_item is not None
+            assert rss_item.enabled is True
 
     async def test_delete_rule_keeps_rss_referenced_by_other_bangumi(self, db_engine):
         async with Database(engine=db_engine) as db:
@@ -65,9 +70,11 @@ class TestDeleteRuleRSSCleanup:
 
             await manager.delete_rule(1, file=False)
 
-            assert await db.rss.search_url(SUB_URL) is not None
+            rss_item = await db.rss.search_url(SUB_URL)
+            assert rss_item is not None
+            assert rss_item.enabled is True
 
-    async def test_delete_rule_comma_joined_link_removes_each_orphan_feed(
+    async def test_delete_rule_comma_joined_link_disables_each_orphan_feed(
         self, db_engine
     ):
         url_a = "https://mikanani.me/RSS/Bangumi?bangumiId=1"
@@ -85,5 +92,28 @@ class TestDeleteRuleRSSCleanup:
 
             await manager.delete_rule(1, file=False)
 
-            assert await db.rss.search_url(url_a) is None
-            assert await db.rss.search_url(url_b) is None
+            for url in (url_a, url_b):
+                rss_item = await db.rss.search_url(url)
+                assert rss_item is not None
+                assert rss_item.enabled is False
+
+    async def test_delete_rule_keeps_orphan_feed_torrent_history(self, db_engine):
+        """停用而非删除：不应连带清掉该 RSS 关联的种子去重记录。"""
+        from module.models import Torrent
+
+        async with Database(engine=db_engine) as db:
+            await _seed(
+                db,
+                bangumi=[make_bangumi(id=1, rss_link=SUB_URL)],
+                rss=[make_rss_item(url=SUB_URL, aggregate=False)],
+            )
+            rss_item = await db.rss.search_url(SUB_URL)
+            assert rss_item is not None
+            await db.torrent.add(
+                Torrent(name="ep01", url="https://example.com/1", rss_id=rss_item.id)
+            )
+            manager = TorrentManager(db)
+
+            await manager.delete_rule(1, file=False)
+
+            assert len(await db.torrent.search_rss(rss_item.id)) == 1
diff --git a/backend/src/test/test_request_url.py b/backend/src/test/test_request_url.py
index 31bb953e..abc209da 100644
--- a/backend/src/test/test_request_url.py
+++ b/backend/src/test/test_request_url.py
@@ -218,6 +218,13 @@ class TestRateLimit429:
         assert result is not None
         mock_sleep.assert_awaited_once_with(HTTP_429_MAX_RETRY_AFTER)
 
+    async def test_get_url_429_with_nan_retry_after_uses_fallback(self):
+        result, _, mock_sleep = await self._run(
+            [self._resp_429({"Retry-After": "nan"}), self._resp_ok()]
+        )
+        assert result is not None
+        mock_sleep.assert_awaited_once_with(HTTP_429_FALLBACK_DELAY)
+
     async def test_get_url_429_with_date_retry_after_uses_fallback(self):
         result, _, mock_sleep = await self._run(
             [