Grace notes on Triplets corrupts file

Steps to reproduce the bug:

1) Create a blank score with a single instrument. (i.e. Time signature = 4/4 - Key = C major)
2) Input in first measure tuplets (3 each beat)
3) Save the file.
4) Open the created file. (Everything is OK at this point).
5) Make some changes (i.e. adding or deleting measures or adding instruments).
6) Save the changes and close the file
7) Open the file again. (Now it is corrupted).

My OS is Xubuntu 18.04.
OS: Linux 4.15.0-43-generic, Arch.: x86_64, MuseScore version (64-bit): 3.0.0., revision: 3543170