U3421WE, dual computers, randomly turning off

Hi, I am using a dual computer setup where my personal desktop computer (Dell Precision workstation) and my work laptop (Dell Precision laptop) are connected simultaneously to one monitor Dell U4321WE. The desktop is connected via DisplayPort and the laptop is connected via USB-C. After switching from the laptop to my desktop, the screen turns itself off after a short while. I believe that this happens when the laptop goes into standby and the monitor somehow detects that the laptop has gone to sleep and does so itself. 

Is there a way to prevent the monitor from turning off? My current solution is to unplug the USB-C cable from the laptop once I am done using it. I would prefer to have the laptop plugged in all the time, especially if I am running something there and want the laptop to keep charging via USB-C.

Thank you in advance