Musescore 4.4.1 - Display and crashing

I've been using Musescore 4.4.1 over the past few days without a problem, creating several scores.

I opened the program this morning to continue work - no problem. But when I loaded the score I was wanting to continue work on, the display was weird. (Screenshot attached).

I tried dragging the elements around to put them back where they usually are, dragging the main score window back to its usual size etc, but nothing seems to dock in place, and then the program crashes.

Any help greatly appreciated.