diff --git a/backend/services/vocabService.js b/backend/services/vocabService.js
index 03efa3f..19df4d4 100755
--- a/backend/services/vocabService.js
+++ b/backend/services/vocabService.js
@@ -2060,22 +2060,19 @@ export default class VocabService {
         ['stage', 'ASC']
       ]
     });
-    const validPool = await this.getCompletedLessonVocabPool(hashedUserId, course.id);
-    const validPairs = new Set(
-      (Array.isArray(validPool?.vocabs) ? validPool.vocabs : [])
-        .map((entry) => this._buildSrsPairFingerprint(entry))
-        .filter(Boolean)
-    );
+    // Do not require a scheduled card to be present verbatim in today's
+    // regenerated lesson pool. Course content can be corrected after a card
+    // has been scheduled; comparing against the regenerated pool then hid all
+    // legitimate older SRS cards. `_isTrainableSrsPair` above remains the
+    // content-level guard for malformed fragments, hints and task prompts.
     const validDueRows = scheduledRows.filter((item) =>
       this._isTrainableSrsPair(item)
-      && (!validPairs.size || validPairs.has(this._buildSrsPairFingerprint(item)))
       && this._getSrsScheduleDateKey(item.nextDueAt) <= todayKey
     );
     const upcomingByDate = new Map();
     scheduledRows
       .filter((item) => (
         this._isTrainableSrsPair(item)
-        && (!validPairs.size || validPairs.has(this._buildSrsPairFingerprint(item)))
         && this._getSrsScheduleDateKey(item.nextDueAt) > todayKey
       ))
       .forEach((item) => {