Why is my podcast artwork being rejected?

I am getting the error message : Podcast artwork must be between 1400 x 1400 and 3000 x 3000 pixels, JPG or PNG, in RGB color space, and hosted on a server that allows HTTP head requests.

I have edited the image in photoshop so that is it a low file size, in RGB color, and has the correct pixel defintiion.

My podcast rss is via podbean, because I was not sure how else aside from soundcloud to host it. ( Open to suggestions though!)

https://feed.podbean.com/astheworldfallsdownpodcast2020/feed.xml

https://feeds.soundcloud.com/users/soundcloud:users:809816323/sounds.rss

What am I missing here?

Thank you !