This was the first usable fact. As you can see from the descriptions, the checking programs have their virtues for MP3 files.
If you want to supply more data, you could make the files available straight after ripping and a copy after you have tagged it.
As a test, you could also tag a copy of an old file which has successfully been tagged previously and see if that remains OK or is also broken.
What size do the covers have?
See e.g. here: