Game frequently starts on the wrong display

I run three displays.

I routinely start the game and find that it's decided to start on a display other than the one I'd previously selected.

Before logging in, I select options, set the game back to the display I choose to use, select keep changes, then save & close.

I've checked both before and after login to confirm the correct display is selected (redundant I know since the game is on the display I selected, but hey, you never know).