I think this has been happening for at least a few days now. Sometimes images just do not load.
On an alt account I use, I went to look at one of my old project pages, and it just refused to load the screenshots at all. When I tried to right click and view the image in another tab, I instead got a Cloudflare page with a 502 Error.
I hope this is fixed soon. It is a royal pain in the butt.