My first idea was that it might be related to display scaling, but it is not. The 2 computers I tried this on are completely different: One is a personal device, the other is from the company I work for.
I just realized that some vital information is missing in my text shown above Sorry.
This is about the Bitwarden extension used inside Microsoft Edge.
So Ctrl- does not have any influence on the window of that Bitwarden extension and a right-click on the QR-code does not do anything.