SDL3 multi monitor on macOS: problematic window placement after leaving fullscreen

I have a multimonitor setup, primary in the middle, one to the left and right.

Going fullscreen always choses the middle, primary screen (except one time). That's good.

However when I leave fullscreen, the window gets placed all over. Mostly to the left monitor but never fully on screen, always parts off screen, preferably in the lower left corner.