Image Not Uploading [Proper Dimensions]

Hello,

For some reason I am not able to properly upload an image on one of my podcast feeds. I have tried the image in 1400×1400, 1500×1500, and 1600×1600. It works when I upload it to all of my other feeds, but for some reason it will not upload and save properly to the one I want to use it on. Any suggestions? Thanks!

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