dual monitors PT slips to main screen

So I open a session that when I closed it, my mixer window was on the 2nd screen.



I close a session and reopen it. Mixer window is now in the main screen and I have to move it to the 2nd screen every time.



System is the same as my 10 system, just with 11.3 on it now. Anyone know why this happens, or is it another PT 11 bug.



Thanks