Speech not working on Dynamic Edit on initial opening

Issue type

Accessibility issue (e.g. for keyboard-only or screen reader users)

Description with steps to reproduce

When trying to edit an existing dynamic mark the screen reader gives no speech until something is deleted/changed.

STEPS:

1. Add a dynamic mark such as mp (best to show with more than 2 characters)
2. Use Alt + arrows to navigate on to the dynamic mark and press enter.
3. Press left and right arrows and notice there is no speech output.
4. Arrow left a few times to ensure that you are at the beginning of the dynamic mark and press delete twice to remove it.
5. Type a new dynamic mark such as fp and notice that the screen reader announces as these are entered.
6. Arrow left and right across the newly entered dynamic and notice that they now do read each character correctly as you move across them. Until you reach the start or the end where instead of stating blank or saying nothing they continue to repeat the previous letter (See #19933 which is particularly confusing if you are trying to tell whether you have ff or fff.

The screen reader should announce each character as you arrow along when the field first opens.

Supporting files, videos and screenshots

N/A

In which versions of MuseScore Studio is this issue present?

4.7

Regression

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

Operating system

Windows 11 with NVDA

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