Temporary hang with particular file/.ini combination

Hi -- MuseScore 3.5.2 and 3.6 release candidate (MuseScore-3.6.0.451381076-x86_64.AppImage) on Linux (Kubuntu 20.10) are hanging for a few seconds for no apparent reason.

Video of the problem: http://caseyconnor.org/pub/musescore/musescorebug.mp4

This only happens with a particular .mscz file, and only if I use my ~/.config/MuseScore/MuseScore3.ini.

If I start with a fresh config it does not happen.

The file was originally a composition of mine (created in v.3.4.2). I have reduced it to the simplest demo file I can manage (see attached .mscz). It needs to have the volta present for the bug. If you remove the volta it does not happen.

1: use the .ini file from here: http://caseyconnor.org/pub/musescore/MuseScore3Development.ini
2: start musescore
3: open the demo file
4: attempt to drag the note up and down with the mouse
5: observe that every few times you move the note, it will freeze MuseScore for several seconds and peg one CPU core at 100% before eventually returning to normal.
6: delete the volta
7: repeat step 4, and observe that it never hangs

The same thing happens when you zoom in and out, etc. It also takes a long time to open the file, or switch to that tab, etc.

I note that this .ini file was created by copying the MuseScore3.ini to MuseScore3Development.ini before running the 3.6 AppImage the first time... perhaps that's not supported? At any rate, I expect the issue should be addressed, so I post in case that's true.

Edit: forgot to mention -- I have not noticed this issue with any other pieces of music, created around the same time as this file, and with voltas, etc. They all work fine. It is only this file.