Audio sync issues on any Plex TV client

Redundant (to existing discussions) question but I’m not sure which of the several audio sync threads addresses my problem. Audio is lightly out of sync (1/2-1 second) via Tivo Plex client (but problem also previously existed in Roku PLex client when I was running that; Plex server version doesn’t seem to make a difference), but ONLY on non-HD .mp4 files. So, only 480p has the issue, never 1080)

I’ve always had this issue and had switched over to jriver software, which fixed my sync problem, via a sound related delay setting in that. I am running the jriver stuff directly from a PC to my TV via HDMI but I’ve purchased a Tivo Bolt box and would like to run everything from there. So that brings me back for another look at the Plex client on the Bolt.

Can anyone point me to what my most likely problem is and what the most likely fix is, before I start trial/erroring everything again (I never did solve the sync problem.)? Thanks

Also, the files have no sync issues at all when played directly via Quicktime or any media player.

Think I’ll just crawl back to my jriver running from PC to TV via HDMI setup. Will check again next year …