Error when putting title to mp3

hello all my problem is that I have my songs in my cell phone and all with its cover put, I put it with mp3tag.mi problem is that the phone has put the cover of a song to almost all songs, but I connect the cell phone and I get the right cover. to an asi volvia put the covers again with mp3tag and nothing remains the same.I've tried a lot of tagging programs but the same thing happens, why?

Could it be that the player on the cell phone connects to the internet and gets a cover from there but ignores locally available pictures?

Here is a thread that deals with pictures on smart phones:

Do you have all that songs with the same cover in the same directory? It may be that your player takes this as an indication that they are songs from the same album.

Do you have filled the album-tag? It may be that your player need this tag to neglect the same directory.

Do you have a cover-file in the directory? It may be that your player takes this cover-file and does not care about embedded covers.