When "Exporting Parts..." (in PDF), lyrics lines are crunched.
When I "Export Parts..." (function that generates one file per part and one file for score+parts, see https://musescore.org/fr/node/278621#export), the lyrics lines are crunched.
Workaround : This does not occur when exporting each part separately.
I just create a sample to try with a brand new files (hereby attached). The bug is reproduced.