Issue with adding screenshots to AppStoreConnect

Question

I've uploaded my app to AppStoreConnect and was working on getting all the data pulled together. Noticing the screenshot page, I took several screenshots of my app via the button on a iPhone 13 simulator. I tried to drag and drop the screenshots, like it should work, into the area. BUT I got this strange error:

I have tried different simulators and screenshots, but none of them seem to work. I've additionally tried to add screenshots for other screen inch sizes, but was unable. It seems quite unreasonable that the px dimensions should be 1242x2688 for a screenshot... considering that is about the size of my laptop's monitor.

Anybody know a way around this? It seems like (another) glitch... But I'm not sure. It would seem like taking a screenshot on the Apple simulator would work with the Apple website, but whatever.

Thanks in advance!