Exporting parts with explicit rest bars to uncompressed xml makes MuseScore quit

Using Mac Catalina OS also Monterey OS
Although I am using current 3.6 release I have checked with the latest nightly build for MuseScore 4.0.0.223250408 Nightly and the same thing happens, so the bug is present in latest source.

Exporting several parts containing multiple bar rests explicitly written with required rest eg breve (4 beat) rest in in 4/4 quits MuseScore after the first part is written.
I require parts to be exported like this with explicit rests for blank bars with the resultant file being processed to produce Sonic Pi format files.

Reproduce example:
export file https://musescore.com/user/131547/scores/5631073 as a midi file (attached)
load it into MuseScore
create 4 parts naming p1...p4
expand rest bars using "m" key
replace each bar symbol by pasting in a breve (4 beat) rest
reselect ful score page and SAVE THE SCORE
try to export all four parts as Music XML uncompressed (*.musicxml)
MuseScore will quit. (The first part file seems to be saved)
Reload and restore the file
Repeat the export again. This (and subseqewunt times) it will work.

This is just one example file, but I find this happens with other files too, which have rests replaced explicity this way. I have used this technique to convert many midi files to work in native Sonic Pi format using a processing script to work on the individual musicxml files for each part.