I'm opening a thread on this because the issue has been there for a few (don't know how many) versions of MC28. I'm running dual displays (Apple Silicon MacBook Pro 13" plus large Benq screen). The large screen is the primary one, the MacBook is the secondary display.
MC starts & runs OK, provided I keep some part of the MC window on the primary display. I can move nearly all the window onto the secondary display. When I do that, the menu bar on the secondary display is active, provided about half or more of the window is on that display.
As soon as I move the window completely off the primary display, it disappears completely, and the menu bar reverts to the primary display. This applies whether I'm in Standard, Mini or Display view.
I've tried rearranging the relative positions of the two displays with no improvement. It looks to me as if MC computes the bounds of the screen in which it starts and then requires that at least some part of its window remains within those bounds.
Quite frustrating as I usually keep MC on that smaller secondary screen to keep it clear of my normal work area.
Regards, Brian
MC 28.0.46 Silicon, MacOS Big Sur 11.5, MacBook Pro (13" M1 2020) 16GB