I've tried adding different art for individual songs but every song keeps defaulting to the first one I did. In the mp3tag it shows the right image and in the Microsoft music thing it shows the right image but in Spotify its not changing they are all the same art.
I tried it in itunes as well and the same result is happening, if I click on the song info it shows the right art but the cover is still the same image as the 1st one.
So it's a player problem?
You should check if you have filled the tag fields for ALBUMARTIST, ARTIST, TITLE and ALBUM.
If not all fields are filled, then probably the player takes the picture from the first file that also has no data in that field.
I still think that if it all shows ok in MP3tag, MP3tag has done its duty. All further questions should be directed to the support of the player.
iTunes will not update automatically. You will need to force it to do this. Google a solution for your platform, there are various Apple and Windows scripts that will correct it for you.
I can’t advise regarding Spotify, but how are you modifying their music that is proprietary?
I think this did the trick I'll put another thread if the issue comes back but thank you and I'll mark it as solved