I’m not sure if this issue was really fixed in 2021.1.20f1… I’m using 2021.2.10f1 / Timeline 1.6.4 and I need to shift the audio clip by 10 frames now to work around the issue.

Similar bug in 2019.2 - In play mode, timeline audio plays immediately, then restarts a fraction of a second later. Subsequently, the animation and audio are out of sync by approximately a second.

The 4 frame workaround suggested in this thread does not work here, the double audio still plays and the animation continues out of sync. Starting the audio later than 4 frames cuts off the start of the audio, but the doubling effect still occurs.

I am having the same issue. Leaving the first 4 frames of the audio track blank in the timeline fixed this for me. I agree this seems pretty janky considering I am trying to create linear content as advertised.

Update:
Check perfectly on my 41 second recording
if one audio starts from 0 frame ends on last then audio is moved exactly 1 second to the left, if audio the same 41 second audio  is moved 4 frames from beginning on timeline, then it is moved 4 frames in recording and cuts last 4 frames of sound

so to workaround for now we must move audio 4 frames and end on last frame then it is the same in editor and in recording, and perhaps in final build, it is like in timeline with a must of 4 frames gap, maybe that gap varies depending on timeline length or audio length, but wll check that on other recording

Well this bug is annoying, it affects play mode, it was fixed in preview of timeline in editor, but it is not fixed in play mode. It also affects Unity recorder.

My observation is when you move the audio track to the beginning of time line frame 0, then audio is somehow moved backward like 1-2 seconds, so it starts form 2 second of the audio track and also ends about 1-2 second earlier.

When you move the track exactly 4 frames from start, so the audio track starts on 4th frame, audio syncs ok or it is moved 4 frames from start and ends 4 frames earlier if the audio track is also to the end of timeline.

So can someone pls check if the audio is moved 4frames it is synced ok on playmode and recorder?

my workaround it to make timeline work exactly on frames perfect and on final record or build I move 4 frames the tracks that start from frame 0

Well ... but is an annoying BUG.

Unity you advertise that you make PIXAR movies on timeline but this is silly come on .!!!!!!