Issue with cover art writing to mp3 files but not to flac files in 3.20

Since installing ver 3.29, I am unable to add or change the cover art on .flac files that are in or being added to my collection, but I am still able to add or change it for .mp3 files. The cover art shows up in Mp3tag but does not write to the file itself as you can see from the pic attached. If I convert the .flac files to .mp3 the image writes correctly just as it has always done. I don't want to convert all new files just to get the cover art to show up in Winamp. I also did not make any changes to settings. Any thoughts would be appreciated.
Thanks!

I don't see any attached pictures

see e.g. here:

How big are your cover art pictures?

There is a limit of 16 MB for embedded cover pictures in FLAC files.

See - for example - here:

AFAI can tell, your picture shows the WIndows Explorer and not Winamp.
So, where don't you see the covers?
If it is the WIndows Explorer, then I do not see many options to get a picture in flac files.

Sorry for omitting the pic. I don't have much experience with forums anymore. I am not doing anything different with 3.29 than I did with any of the previous versions over the years. To be sure I spot checked the file sizes, none are over a meg & most are generally ~500k or less. Also the pics work as before as long as I convert the flac files to mp3 which makes no sense. The timing to me is suspicious as this issue only started after I upgraded last March/April. I could try a clean install but the time to import all 12k+ would be daunting. I think I will dig out an old laptop & see what happens if I do a clean install & import a few dozen folders. Thanks for your suggestions.

The linked threads offer some more ways to test what the cause may be.
Which did you try with which result?

Just to be sure:
Do you speak about the small preview picture in the Windows Explorer?
The one that currently looks like a white paper with the Winamp Logo?

Do you want to see the real embedded cover art picture there for flac files?

Yes LyricsLover, that is what I am talking about!! Thank you for figuring out what I was trying to get at.
Getting the cover art to show up on the explorer icon instead of the winamp logo. It always showed up via updating through Mp3tag unless it was already native to the file I was importing until 3.29 came along. Now only mp3 covers show up in Explorer after updating but not flac.

If your issue is that cover images are not being written to FLAC files, then when you reload those same FLAC files into Mp3 tag, their covers should be missing. Are they in fact missing? If not, that means the covers are being written to your FLAC files by Mp3tag but Explorer is simply not showing them. That is a whole different kettle of fish, as they say.

Your MP3 vs FLAC icon display issue may reflect a difference in your Explorer View settings for the parent folders for each type. Try using larger icons for FLAC.

If that fails, there is an excellent freeware utility called Icaros Shell Extensions that will almost always solve icon display problems in Explorer (which are very common). I have used it for many years.

Good idea.

Icaros can provide Windows Explorer thumbnails, for essentially any video media format supported by FFmpeg, this includes popular filetypes such as: Mkv, Flv, Avi, Mp4, Mov, Rmvb, M2ts, Ogm etc.

Besides the FFmpeg supported filetypes, Icaros also contains custom parsers, which can produce Cover Art thumbnails for Mkv, Flac, Ape, Mpc and several other filetypes.

My current Icaros settings:

Thank you Doug_Mackie! You were absolutely correct. For some reason, I decided to do some cleanup in my system & uninstalled Icaros right around the time that 3.29 came out. I just installed 3.3.3 & all is right in my thumbnail world again. I guess I am getting more forgetful of tech details as my retirement moves along. Lesson learned. Thanks again to you & LyricsLover for your help. Have a great summer!