Playback of VST3 plugin not working with one library but working with others

Issue type

General playback bug

Description with steps to reproduce

1. Use in a score VST3 "Play" with library "Symphonic Choirs" from East West

Actual Behaviour:
Playback doesn't work using Play VST3 plugin with the library EW Symphonic Choirs.
Strangely, playback does work using the same plugin with a different library.
Playback sound preview, editing and clicking on the notes, works fine with both libraries.

Expected Behaviour:
Playback should work for both libraries from the same plugin.

Supporting files, videos and screenshots

https://github.com/user-attachments/assets/8301ea99-5515-4c8c-a9f5-f12372a4b714

Plugins in the video:
Soprano: VST3 - East West Play | Library: East West Symphonic Choirs
Violino: VST3 - East West Play | Library: East West Symphonic Orchestra
Tromba: Random MuseScore instrument

In which versions of MuseScore Studio is this issue present?

4.7.0 - 4.7.3 (also present in 4.7.4-260704051 rev.65ad8c2)

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

OS: Windows 11 Version 25H2 or later, Arch.: x86_64

Additional context

Versions Affected:
All 4.7.x versions included nightly (64-bit) 4.7.4-260704051, revision: 65ad8c2
Everything was working as of 4.6.5

Similar Issue (Closed):
No sound during playback with VST (4.7 nightly only) #30366

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible