Mouse won't go back to server monitor

[Josh Rotert 0]

Hello, I have Windows 10 setup as server and MacBook Pro as client. When I go from Windows to the Mac, it won't go back to Windows. It tries to go but is immediately taken back to the edge area of the Mac screen. Mac version 10.11.6. I turned off Hot Corners on the Mac with no luck. Please help. Thank you, Josh