Android - Changing play tone note pitch breaks touch navigation

[martinwork]

Describe the bug

In Android Chrome or the app, opening the note frequency keyboard triggers a text editing dialogue. After closing that, touch navigation is broken until the page is refreshed.

See description in report about Android app:
microbit-foundation/microbit-android#91

If I request the desktop site in Chrome, the problem doesn't occur.

To Reproduce
Steps to reproduce the behavior:

1. Create a new project
2. Add a play tone block
3. Tap Middle C
4. Close the dialogue
5. Try to move a block
6. See error

Expected behavior

Editing a note should not break touch.

I suspect the keyboard should work with touch, so the text editor need not open until the note pitch number is tapped.

micro:bit version (please complete the following information):

not hardware related

Desktop (please complete the following information):

• OS: Android - all tested versions
• Browser [e.g. chrome, safari] Chrome and app
• Version [e.g. 22] All tested