I’ve had problems uploading screen snaps lately. I run the latest Mac OS on a 2021 iMac with Retina display. See this thread for an example. The other party could not see it on-screen or download it to view it.
Probably a website quirk.
I recently bought an Android tablet to surf the web, bad idea lol!
Every popup takes over the screen, and that is just the beginning of the nightmare, back to laptops.