Unable to open combo box after reinitializing the editor

[KarolDawidziuk]

Type of report

Bug

Provide detailed reproduction steps (if any)

1. Go to https://codepen.io/slewthsloth/pen/oNyoEya?editors=1010
2. Click on the editable (triggers focus, which enables toolbar commands).
3. Open the font toolbar dropdown.
4. Click outside the editor to invoke the blur event and disable the toolbar commands.
5. Click the "Destroy 1st instance" button.
6. Click "Create 1st instance" again.
7. Try to open the same dropdown in the toolbar.

Expected result

The combo box opens correctly.

Actual result

The combo box is not opened. There is an error in the console.

Uncaught TypeError: Cannot read properties of null (reading 'getElementsByTag')

Other details

This can be related to blur event but there is more investigation needed to confirm the cause of this issue.