podcast cover art not accepted

Hi! I'm attempting to submit my podcast to iTunes but it's saying the cover art is not meeting the specifications.

I've triple checked the thumbnail and widescreen photos for the pixels, dpi and file size and everything seems to be correct.

I also removed the Souncloud account because I read that their specifications could be different for their photos.

But, either way, iTunes still says the only thing off is the cover art. I've looked in forums and other people have had this issue. I've been trying to troubleshoot this for the longest time. Any help is appreciated. I'm totally baffled. What am I missing? Thanks!