Switching via key combination requires the Dell Display Manager (or equivalent software). If this software is only installed on one computer, switching from this system to the other works without any problems, but then you have to go back via the menu on the screen. The reason for this is the way it works: when the stored key combination is pressed, the DDM sends a "Switch to input X" command via DDC/CI (https://de.wikipedia.org/wiki...) to the monitor, which switches the video input accordingly and also switches the USB ports. The monitor therefore "knows" nothing about a key combination. The advantage of this solution is that the key combination can also be entered on the notebook keyboard (which is not connected to the monitor). The disadvantage is that both computers require the corresponding software. Incidentally, ddccontrol can be used for this under Linux.

Splitting the screen area into virtual parts has nothing to do with the screen and only affects the window manager of the operating system. As an alternative to the Dell Display Manager, FancyZones from Microsoft (https://learn.microsoft.com/en-us...) can also be used under Windows. If you work with KDE Plasma under Linux, the function is already integrated (press Meta + T to configure and hold down Shift when moving the windows).

Hello, good day Mr Hiestand
I have even attached a third laptop on occasion, without software (Displaymanagaer) on it, and it also works because the main computer has it when both are supposed to work together. it also works when each laptop or pc is connected separately.
Good luck, or better success? :-)
pGI