ipad versions can run on both MacOS and VisionOS (if the functionality is supported on those platforms). You can test against VisionOS as it has a simulator like iOS/tvOS. Bit harder to test against hardware, if you don't have the funds to buy a Mac or Vision Pro device. You could ask someone whom does have a Mac/Vision Pro to test it for you, you would need their email address to add them to a test group for your app though (this would use the Apple Testflight approach.)

I am getting the same issue with my account today, seems to have only happened recently. I have done similar to you in trying to remedy the issue by changing browsers etc.. to no avail.