A sequence made from a sequence actor component doesn't play audio in editor or in PIE when the child of another actor or track.
This was reported and tested in 4.22.3 (CL-7053642). This was reproduced in 4.23 (CL-7838574) and Main 4.24 (CL-7887407)
Results: Play the sequence, notice there's no sound. Start the game, notice there is sound but this only happens when audio is a child track (spatialized)
Expected: Audio plays in Editor when playing a Sequence from an ActorSequence component. Audio plays in game (and editor) when the track is spatialized (a child of another actor)
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-78580 in the post.