What file types does this happen to?

All of them seems to be m4a types. I could always reproduce the problem, however, I think I found a workaround in the mean time:

Remove the file from the database (Ctrl-Delete), than add the file again, analyze the file, change the metadata (eg YEAR), rescanID3 tags...now the data is kept. If you do another file analysis now, the value is kept also.
I don't know yet if this will work for all files. I'm still troubleshooting.

I also notice that changing the volume for a particular songs is sometimes stored and sometimes not. When reloading the file, the volume fader goes back to the center rather than the volume increase I've dialed in.

Thanks Chad!

Good work man. Let me know the rest of your results.

OK Chad, I can now confirm that the workaround is "working". So in case you need to reanalyze the songs, and some of the ID3 tags have changed after the analysis (in my case it was the date, comments and album information which always changed) you need to follow these steps:
1. Delete the song from your library (control-delete)
2. Add the song back to the library
3. Re-analyze
4. Change the ID3 tags (e.g. year, album information…)
5. Rescan ID3 tags (this is just a check to be sure that ID3 information is kept)
6. If you would re-analyze the song again, the changes made in the ID3 tags will remain
So I might think that this is some kind of inconsistency in the database that needs to be resolved? I haven’t figured out yet why the volume is sometimes not being saved with the song. Maybe also related to this inconsistency but I am not sure.

Dirk

Aces!