Mnemonic Shortcuts not reading or working correctly

Issue type

UI bug

Bug description

When arrowing down a menu the Mnemonic shortcut symbols are not read out by the screen reader. They work if pressed in quick succession, but if interrupted by an arrow key press they do not work and seem to loose focus so Esc has to be used to get back to the score and then other attempts to use Alt for a menu do not work as if a menu is still stuck open but not in focus.

Steps to reproduce

1. Press Alt F to open the file menu

2. Arrow down to Open.
   You hear "Open Ctrl + O"
   Expected result is for the Mnemonic shortcut to be read also and hear "Open Ctrl + O O".

3. Press Alt F O in quick succession. The Open dialogue menu opens as expected.

4. Press Alt F, arrow up/down the menu a few times hearing items.

5. Press O.
   Expected behaviour - The Open dialogue box should Open.
   Actual Behaviour - The focus seems to be lost, arrowing and tabbing don't work, in fact nothing but Esc seems to work which returns focus to the score.

6. Press Alt + F to return to the File menu.
   Result - Alt no longer seems to work and although the score can be navigated even trying to quit the programme can get stuck in an unfocused dialogue box asking whether you want to save changes.

Screenshots/Screen recordings

No response

MuseScore Version

4.1

Regression

I don't know

Operating system

Windows 10 with NVDA

Additional context

No response