Crashes adjusting frame height and gaps

OS: macOS Mojave (10.14), Arch.: x86_64, MuseScore version (64-bit): 3.0.5.21343, revision: 58dd23d

I've tried to make a reproducible test case, but failed. I just made an extensive document,
http://musescore.com/bsg/continuo2 , whos substance is systems separated by many paragraph-length vertical frames with text (not text frames). About half the time, after pasting in and adjusting the text, if I'm not careful to save the file in advance fearing a crash, I try to adjust the frame height or top or bottom gap from the inspector, usually, with the up-down arrow controls, I get a crash. I was getting crashes every 5 minutes until I became meticulous about saving to prevent it (as with the apocryphal doctor visit, "then it doesn't happen"). But this has been majorly frustrating.

I also frequently saw systems on the non-first page flash back and forth between long and short instrument names, always corrected to "short" when I saved the file. I have "hide empty staves" enabled.