Insert bar before gracenote with slur results in deletion of slur

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.2.3.7635, revision: d2d863f

1. Create an empty score.
2. Add a note in bar 1 and in bar 2
3. Add a grace note to each main note
4. Add slurs from the grace notes to the main notes
5. Insert one or more measures immediately before bar 2
6. Result: the slur in bar 1 remains correctly placed; the main note and grace note in bar 2 are shifted right to accommodate the inserted bar(s); the slur attached to the note in the original bar 2 is not shifted right.
7. Save score
8. Re-open score
9. Result: the misplaced slurs are no longer shown - i.e. neither in their misplaced nor their "correct" position - they have just disappeared.

Other information:
- The same behaviour occurs for all types of grace note, and for groups of grace notes.
- A tie between a grace note and a main note is not affected - i.e. it moves with the notes.
- Selecting the misplaced slur and inspecting the offset of the slur shows zero offsets.
- The "elastic" lines shown after double clicking on the misplaced slur indicates that it is still associated with the grace note and main note.

This behaviour is a particularly annoying as it is very rare that a grace note is not slurred onto the main note and all grace note to main note slurs in a score that occur after the insertion point of the new bars are affected and have to be replaced after bars have been inserted.