[MU4 Issue] Applying "Break inner beams" over rest only creates a "joined beam"

[DavidMcCaulley]

Describe the bug
When applying any of the "break inner beam" options from the palettes over a rest, the visual result isn't that the beam goes over the rest with a beamlet in the correct place, but that the entire beam is joined over the rest (as if I had applied the "join beams" option).

To Reproduce
Steps to reproduce the behavior:

1. Enter a 16th note, followed by a 16th rest and two more 16th notes.
2. Click on the rest and try to apply the "break inner beams (eigth) option from the palettes
3. It looks as if only the "join beams" option has been applied

Expected behavior
The beam should look as it was in MuseScore 3.6 when applied with the same palette option. There is a workaround I found (see video below) using the properties panel, but this is quite time consuming.

Screenshots
The desired outcome when using the palettes:

Video of the actual result (including the workaround):

MS4_BeamBreak_overRest.mp4

Platform information
OS: macOS 12.0, Arch.: x86_64, MuseScore version (64-bit): 4.0.0-223472200, revision: github-musescore-musescore-5485621

[abariska]

@oktophonie Please, take a look