Hey, i got for myself 3rd Monitor and made it for Portrait mode. The problem is i got a deadzone at the bottom of monitor and everytime i turn on pc its there. 1 time fix is changing display orientation and switching back.
what are specs of the PC?
What monitors? what resolutions?
I assume those details might help figure it out.
looks like it started that bug in win 10 1803
For others who find this conversation / bug - Here is the solution I found last night:
Essentially, Microsoft introduced a bug in Windows update where portrait mode does not work properly (introducing a black area at the bottom of the screen) with MAME console games unless it is using the Microsoft Direct3D API. Once I turned that on, it displayed correctly.