Optiplex 7490 blicking OS interaction on switching display source

Hello all,

I have an Optiplex 7490 AIO computer that receives a signal from a different PC, and has a outward display connection to one external monitor and a video recording device. I need to set it up, so that the optiplex is displaying a video from the different PC, but when I do, the system becomes unresponsive. I have an additional monitor connected as mentioned, so I'd imagine this wouldnt be an issue. Is there a way for the optiplex to do as I described? It is a case where i need the set up to work in that way specifically.

Thank you for all help in advance.