Setting "Apply selection to all staves" to off on sound flags doesn't work for two sound flags at same beat position

[avvvvve]

Issue type

General playback bug

Bug description

https://github.com/musescore/MuseScore/assets/20806406/44b6bf4c-4e96-40d0-8a60-e67ca1fd56de

Steps to reproduce

1. Create a two-staff instrument with a Muse Sounds sound (i.e. add an extra staff to a Vibraphone)
2. Add a sound flag to the first staff, select the first sound in the list, and uncheck "Apply selection to all staves"
3. Add a sound flag to the second staff, select the second sound in the list, and uncheck "Apply selection to all staves"
4. Hit play, hear that the second staff doesn't play the sound flag sound

Screenshots/Screen recordings

No response

MuseScore Version

MuseScore Studio version (64-bit): 4.3.0-241231433, revision: github-musescore-musescore-5f36e74

Regression

No.

Operating system

OS: macOS 14.1, Arch.: x86_64

Additional context

No response

[avvvvve]

@bkunda Oh boy, a candidate for the 4.3 patch release! I didn't notice this option til this week (it was added in #22408 while I was on vacation it seems, so I didn't know to test it).