Always Fullscreen upon opening MS4 - iMac

No matter what I do, every time I open MS4 on my iMac, it opens in fullscreen. I'd like to have it open in a standard sized window (i.e., not fullscreen).

I have tried resizing the window, closing the program and reopening. No change.

I have also tried resizing the window, closing the program, restarting the computer, and reopening. No change.

No point in adding a file as it seems to work fine for Windows and Linux users. Or maybe I'm just lucky?