My setup:
Logitech Media Server Version: 7.9.2 - 1565967976 @ Fri Aug 16 17:16:14 CEST 2019
Player Model: Squeezebox Touch, Firmware: 7.8.0-r16754
Plugins: A few, but nothing unusual.
Applets: EDO, but same behavior without EDO
No custom-convert.conf file

All my music is FLAC at various sample rates, and those files all play fine. But I also have a large number of spoken-word recordings in MP3 at various sample rates from 8000Hz to 48000Hz.

Those MP3s used to play. But now, 18 months since I last listened to them, only the MP3s encoded at 44100Hz will play. The others appear to play -- the elapsed time in the UI changes, I can seek and pause/play, etc -- and their sample rates are correctly displayed in the LMS UI, but no sound is actually produced at the digital or analog outputs.

With logging enabled for processes that looked relevant (formats.audio, player.source, player.streaming, player.streaming.direct), I can see that the player enters the BUFFERING-STREAMING state for the 22050Hz file vs. the PLAYING-STREAMING state for the 44100Hz file. But I don't see anything to indicate why that's happening.

Since the files last played, I've made only one hardware change: Last year, my old Touch was starting to have intermittent connection problems, so I replaced it with a new Touch, which works great in all other ways. I've made no other changes except for regularly updating the LMS software.

If I resample the MP3 files to 44100Hz MP3, they play fine. So I can do that if necessary, or transcode them to FLAC to keep the audio quality from degrading. But I'd prefer to keep the files unchanged if I can, especially since they all used to play.

Any ideas for why these files no longer play, or for steps I can take to try to make them play?