Thank you so much for all your advice. I tried several of your suggestions (though a few like the EXIF extension I don’t know how to do).
What I DID do that worked was found ONE photo that worked for whatever reason, then copy and pasted every other graphic on top of it in a photo program and saved it, then reassigned the graphic in iTunes. That seemed to work (took four hours to get through them all but it’s done!)
and yes it is a mac 
