I am currently working with a dual screen. When I switch Solidworks to my secondary screen, a problem occurs when I click (in almost all possible circumstances). The attached image shows the problem when I click on the bottom of the window. The screen seems to duplicate itself inside the software. I don't have this problem when I'm working on my computer screen.
Thanks to Ludo.mai, I use solidworks on a window partition of a macbook pro 2018 and when I was plugging in my second 27-inch screen to work on solidworks there was this problem that you describe.
The solution is to go to the window settings, go to the system category then display, put yourself in screen n°2 then change the size of the text ect until on the second screen there is no longer this problem. For me I had to go up to 200% for it to work