Mousewheel scrolling just stopped working

Linux (Ubuntu Studio 24.04), MS 4.4.4.

I had a few scores open for a couple of hours, doing some sketching. Then I went to copy some material that was getting in the way into a new document, and found that the mouse's scroll wheel wasn't functioning.

However, double-finger swiping on the laptop's touchpad did scroll.

And, the mouse scroll wheel functioned correctly in all other applications.

I worked around it by saving everything, quitting, and reopening MS. Then it was fine.

I saw old thread https://musescore.org/en/node/285016 -- related but not exactly the same.

Mainly reporting -- since there's a workaround, it's not a showstopper.

hjh