Disappearing cover art from music directories/folders

I use thumbnails for all my picture, video & audio files. Icaros helps with the video files & MP3Tag helps with the music cover art. At least it did until last week when I updated to v2.86.
After applying the update like usual I read the release notes about the Library & decided to apply it to my two major music directories.
Last Friday I finally had some time for music & when I went to my folders, none of my mp3s had any cover art (see attachment). None of picture or video thumbnails disappeared, just the mp3s. When I went into MP3Tag & looked at a file, the cover art was still there.
I unchecked the Library setting but that did nothing to bring the cover are back.

Does anyone have any idea what might have happened & any possible cure to bring them back?

Thanks for your consideration to my plight!

BTW, I am running Win 10 pro, fully updated & there hasn't been an update since I went to v2.86. I use WinAmp for playback.

Sorry for the double attachment...

check if you have a file called folder.jpg in the folders that show the covers and whether such a file is missing in those folders that don't.

Thanks for the idea. The majority of my folders have these 'hidden' .jpg files. Can & how do I attach them back to the mp3s??

There is an action for that: Import cover from file.
As filename format string use either
(this takes the first jpg-file in the folder)
or whatever the actual filename looks like.

Thanks for your thoughts ohrenkino but I figured out the root of the problem was with Icaros & not with Mp3Tag. I uninstalled it & all my covers came back. I still don't know exactly what caused it to hide the covers but at least I have them back.