Hello @danielstark57 and thank you for posting on our StarTech.com Community!
The mouse switching feature for the P4A20132-KM-SWITCH will only allow the mouse to work on the computer’s main display. If a computer has multiple extended displays, the mouse pointer is unable to roam to any secondary extended displays. This is meant to be used with systems that have just one monitor per computer.
I am very sorry for the inconvenience.
Sincerely,