What is the problem?

After selecting "Block quote" if I select another formatting option the current selection appears blank.

The "Headings" menu is blank:

No formatting option is highlighted:

Steps to reproduce problem

1. Edit any page with VisualEditor
2. Type in a word
3. With the cursor still on that word, open the "Headings" menu and select "Block quote" (or press Ctrl+8)
4. Open the "Headings" menu again and select "Heading" (or press Ctrl+2)

Expected behavior: The "Headings" menu shows the currently selected format as "Heading"
Observed behavior: The currently selected format appears to be blank. Nothing is highlighted in the dropdown.

Environment

Browser: Firefox 78
Wiki(s): https://en.wikipedia.org VisualEditor 0.1.2 (13f8d7d) 01:25, 18 May 2021