Tempo change while loading audio samples causes some instruments to retain old tempo

Issue type

General playback bug

Bug description

If you open a score containing a lot of instruments and quickly change the tempo before all samples are fully loaded, some of the instruments will have the old tempo and some will have the new tempo.

Steps to reproduce

1. Open a score containing many instruments.
2. While the instruments are loading, change the tempo marking.
3. Press play and hear the error: only some instruments have the new tempo

Screenshots/Screen recordings

No response

MuseScore Version

4.2.1

Regression

Yes, this used to work in MuseScore 3.x and now is broken

Operating system

macOS 12.7.2

Additional context

The attached MuseScore file illustrates the issue quite well; just open it and quickly add a "1" to the tempo marking before the samples fully load, to make it 180 bpm. Hit play to hear the problem: all the notes should play in unison, but they don't.

Tempo Bug.mscz.zip

Note that the issue is probably more likely to occur with Muse Sounds, which takes longer to load than MS Basic (not sure about VST instruments). And it's entirely possible that this would hardly be an issue on super fast computers, where the samples load quicker. I am currently using a 2014 Mac mini.