Odd document window appears when dragging across monitors

I'm using two Full-HD monitors, my OS is Windows 11.

When the single monitor is used, documents open normally, as they should to.

However, when the second monitor is connected, and I drag the Acrobat window across monitors, some odd window of the same document appears, which seems to be useless and not-clickable. It is quite annoying. What can I do?

Here is a video of the problem: