Video wall loses signal when i unplug or plug any pc or mac

Hi, i need a solution for an event that i have to organize shortly, in a matrix different speakers will plug his computers (mar or pcs) to show powerpoints in a video wall, the last year i used a matrix to plug computers but everytime i pluged or unpluged any computer the video wall loses signal and i had to switch off and switch on again the whole system so i need some hardware that allows me to connect and disconnect any mac or pc computer without losing signal in the video wall.
Any idea....

Video wall loses signal when i unplug or plug any pc or mac