Can't click on desktop

Hi,

I've configured my top-left corner of the screen as active angle, by selecting the option "Display" from the dropdown menu. Unfortunately, every time my mouse touches that angle, and all apps are hidden, so that I can see the desktop and do something on it, I can't click on anything on it. Besides not being able to select any file by clicking on it, I can't even right-click on any empty point. However, I can click on my Dock.

I'm using 2 external screens connected to my mac via usb c through a dell USB hub, + the Macbook screen, and this happens only on one of the external screen, which is the one selected as main screen. But if I try to right click or select a file on the other 2 screens after touching the same active angle, I can work fine on my desktop.

The latest version of DisplayLink is installed.

Do you know what may cause this, and how to fix it?

Thanks,

Francesco