When percussion panel and mixer are horizontally docked together, changing a sound in the Mixer resets manually-set panel widths

[avvvvve]

Should be addressed with the bottom-docked panel behavior project: #22016

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Open the Mixer and the Percussion panel (via selecting an inpitched percussion instrument)
2. Drag one to the side so they dock side-by-side
3. Hover between the panels and click and drag to make one wider
4. In the Mixer, change the sound of the selected percussion instrument
5. See that the panels reset to 50/50 width

Supporting files, videos and screenshots

perc-panel-horizontal-resize-mixer.mov

What is the latest version of MuseScore Studio where this issue is present?

Nightly

Regression

No.

Operating system

macOS 15

Additional context

No response

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