Issues linking files to Tags

I am getting in touch with you to request your guidance with the following issue. The other day I wanted to link WAV and FLAC files to their respective JPG Tag (CD covers), using of course Mp3tag, I have done this successfully several times in the past. However, this time I noticed that once I had uploaded the 6 folders on to the music server, none of the tags/covers appeared on the screen.

After that attemt failed, I played the same files on my computer using the Groove Music App to see what might be wrong. This time, only the folders containing FLAC files showed the tags and those containing WAV files didn´t.

Is there any clue that you could give in order to solve this problem? As mentioned before, this is the first time I have had problems linking tags with music files using Mp3tag, a situation that has affected 6 music folders in the past 2 weeks. I would also like to say that I am working with the latest Mp3tag update (v3.16)

Hello, does anyone know what could be wrong and/or how to possibly solve the problem reported in my previous post 5 days ago?

What do you mean by "link" files to jpg tag (CD covers). Artwork is available in two ways typically. One is that the art is embedded within each file. The other is that there is a single file within the ALBUM subdirectory (typically named either "folder.jpg" or "cover.jpg". Please clarify.

If a player apparently does not have the correct support for metadata in certain file types - what should MP3tag do about it?
It would be up to you to investigate which features the player of your choice has and then see where MP3tag can help you (e.g. export the embedded covers to a specific filename).
But if your player has no satisfying features then the only way out would be a different player.

Or another media format. I don't see any need to use the wave format, which is generally poorly supported or not supported at all with regard to metadata, where there is also the lossless flac format.