Layout (Instruments) panel is not updated properly after adding new instrument (after open all parts)

[DmitryArefiev]

Issue type

UX/Interaction bug (incorrect behaviour)

Description with steps to reproduce

1. Create score from Orchestral template
2. Open all part
3. Add Flute
4. Notice it appears at the bottom in Layout panel

All fine after reopening score

Supporting files, videos and screenshots

bandicam.2025-03-12.17-13-59-212.mp4

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

4.5

Regression

No.

Operating system

Windows 10

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