I am recording my choir for years with Audacity on a Windows 11 machine and exporting the recordings as FLAC, 48kHz, 16-bit, level 8 compression. Since 3.7.3 (at least 3.7.4) the recorded FLAC files do either not open properly or do not play back properly. The playback stutters and sounds slurred (lower in tone). When I revert back to 3.7.2, the loading and playback of recorded FLAC files is working properly.
This is a forum where useres (try to) help other users and not a hotline to the developers. Although it is possible that developers look into the forum from time to time, you should not expect an immediate anser from them here.
Does this also happen when you play back using a different program than Audacity?
If an older version of Audacity works for your needs, you can easily download that from the list of old versions on their website.