I'm having difficulty using my surface pro 11 with flex keyboard as primary computer, and my desktop as a secondary computer. 

For some reason, it works fine when my desktop is the primary computer with my wired mouse wired into the primary desktop, but when I try to reverse the situation - meaning plugging my wired mouse into my surface pro 11 and using it instead as the primary computer so that I can use my touchpad on the flex keyboard to navigate my desktop computer's monitors - the desired behavior fails.

This basically means my mouse is stuck on the surface pro 11 screen no matter if I use my touchpad or my mouse wired into my surface pro. 

My apologies if my explanation is a little convoluted, I could not see any other way to describe it.

I am available for further questions, have attached relevant screenshots.

Thank you for any help you are able to give,

Alan