Rename your upload file to something like (name)-2 and then drag and drop the file into app store connect. I noticed when uploading 3 that only 1 uploaded and the other two failed. I believe when they fail their names are stored somewhere. And that prevents any uploads of the same image. I'm not sure if dragging does anything. But definitely rename and drag & drop, one at a time for now.

I was able to resolve this by changing my local file name to have a -1 and re-uploaded the image. This worked fine. It appears this issue happens when uploading multiple screenshots at once. Only 1 image is uploaded and the others appear as errored. If you remove these, I think Apple must be still storing the file names somewhere. It seems like the bug keeps occurring when you upload the same file name

Also having this issue

 @jeremyhu This is just incorrect lol. I have an external hard drive formatted with APFS and I moved my CoreSimulator folder over there into /VolumeName/Library/Developer and cleared my local Caches folder and made sure to kill all simulators. Yet still the simulator cannot load