[MU4 Issue] [Muse Sounds] Muse Sounds permanently stop playing after several tempo changes

[metasekk]

Describe the bug Muse Sounds playback is permanently muted when reaching a certain measure (and beyond) if the score contains the following tempo markings in this order (but wherever you put them): ♩=80,♩=70,♩=75,♩=60,♩=70,♩=40,♩=70,♩=50,♩=75,♩=70,♩=40.

To Reproduce Steps to reproduce the behavior on your own:

1. Create a new score with at least 400 bars and with the instruments of your choice (for instance, a String Quartet).
2. Be sure to have MuseSounds active for at least one staff.
3. Put the following tempo markings wherever you like in the score, but in this specific order: ♩=80,♩=70,♩=75,♩=60,♩=70,♩=40,♩=70,♩=50,♩=75,♩=70,♩=40
4. You should hear no playback after a certain measure, generally located far away in the score (more than 300).

To reproduce it rapidly, I provide two test scores:

Either

1. Open the score Measure_569.zip
2. Go to measure 568 at page 19.
3. Click on any staff at measure 568 and click 'Play'.
4. You should observe the silence of the staves using Muse Sounds from bar 569 onwards.

Or

1. Open the score Measure_367.zip
2. Go to measure 366 at page 8.
3. Click on any staff at measure 366 and click 'Play'.
4. You should observe the silence of the staves using Muse Sounds from bar 367 onwards.

Steps that I have found to bypass the issue:

1. Remove the last tempo change (♩=40)
2. The playback is now working correctly in the whole score

Expected behavior During playback, any staff using MuseSounds should play wherever it is located in the score, regardless of the tempo.

Screenshots I provide a video. Note that the bug is also responsible for the weird artefact that you can hear everytime I start the playback (at 0'21, 0'37, 0'54,...). This sound artefact (on the bassoon staff) also disappears when I remove the last tempo marking (♩=40) at bar 477...

Platform information

• OS: Windows 10 Version 22H2, 64 bits, x64-based processor
• Tested and verified on: MuseScore Beta version (64-bit): 4.0.0-223362132 with MuseSampler v.0.2.4 ; Beta Nightly 223440501-4.0_rc-24b8e34-x86_64 with MuseSampler v.0.3.1 ; MuseScore Release version (64-bit): 4.0.0-223472200 with MuseSampler v.0.3.2

Additional context This weird behaviour is related to the last tempo marking (♩=40):

1. Go to the last tempo change (♩=40)
2. Slightly increase the value from 40 to 41: Muse Sounds playback now works two more bars before being mute
3. Slightly decrease the value from 40 to 39: Muse Sounds playback now works for two bars less before being mute
4. And so forth...

It is therefore very incapacitating: after the first ten tempo markings, none can be added anymore without muting MuseSounds beyond a certain bar.