Hello! Sorry for the trouble and thanks for the test data, it really helps.
So at least with UE 5.6, it looks like the problem is we don’t clean up the imported Sequencer entities once we exit the section and go into post-roll (when playing forward) or pre-roll (when playing backward).
We’ll fix this in 5.6.1 or 5.7, but the fix boils down to replacing the two early return statements inside `FEntityLedger::ImportEntity` with the following:
bool bUnsupportedPrePostRoll = false; if (ImportParams.bPreRoll && (Params.EntityMetaData == nullptr || Params.EntityMetaData->bEvaluateInSequencePreRoll == false)) { bUnsupportedPrePostRoll = true; } else if (ImportParams.bPostRoll && (Params.EntityMetaData == nullptr || Params.EntityMetaData->bEvaluateInSequencePostRoll == false)) { bUnsupportedPrePostRoll = true; } if (bUnsupportedPrePostRoll) { if (EntityData.EntityID) { // If we are reimporting an existing entity and we entered a pre/post-roll time range // that this entity shouldn't update in, we need to delete that entity. Linker->EntityManager.AddComponents(EntityData.EntityID, FBuiltInComponentTypes::Get()->FinishedMask, EEntityRecursion::Full); EntityData.EntityID = FMovieSceneEntityID(); } return; }