Final Cut Pro out of sync on export

Sharing this comment from another thread on the same problem in case it's helpful to anyone:

Following up here. We have not found any solution to the problem yet, however we did finally find a serviceable workaround. We were able to export an XML of the problematic edit to Logic and then could edit our audio in logic without the doubling audio problem OR export the individual LAV and BOOM from Logic as individual WAV files and then edit as needed in FCPX. Not ideal but we were able to wrap up this particular project.

One thing worth pointing out - I did notice on comparing the exports with the "doubled audio" problems - I brought the exported audio back into Final Cut and attempted to see if I could line them up manually. One of the individual tracks would shift left/right a frame or two and sometimes were even retimed completely - not lining up at all - seemingly from cut point to cut point. I don't have the screenshot with me on this machine otherwise I'd share it. Hopefully FCPX will address in an UPDATE very soon.

I don't recall ever having audio sync issues. A couple things come to mind:

How are you monitoring? Computer speakers or with wireless headphones/airpods?

When FCP behaves strangely, a common troubleshooting step is to delete its Settings/Preferences. Hold option and command while launching FCP and choose Delete Settings (or Delete Preferences if you're using an older version). FCP will open the default Untitled library. Configure the Settings/Preferences back to way you like (turn off Background rendering, etc.) then reopen the library you were working on and see if the issue has been fixed.

We’re having the same issue here. You hear the echo at random times while playing back in fcpx. You can restart the played and then it goes away. Upon export some parts have the echo, but then some do not. Seems random. Have tried exporting separate audio tracks (boom on one wav, Lav on another wav) and I can see the issue is randomly appearing on just one of these tracks. No effects or filters are used. Have also tried 2 different computers, have done a clean install of fcpx. No luck. Anyone out there find a solution?

What version of FCP on each of the machines? What macOS on each of the machines?

Run an etrecheck report from https://etrecheck.com after giving it Full Disk Access. Go to System Settings->Privacy & Security->Full Disk Access and enable Full Disk Access for etrecheck. Paste the report in your reply using the "Additional text" button below. 

Check your audio bit rates are consistent on everything.

Al

Audio bit rates don't matter, what does matter is sample rates.

Sequoia 15.2 on all 3 machines

fcpx 11.0 on all 3