Bug: Firefox, exiting fullscreen in Scratchpad UI locks focus to side menu toggler

[jimbonothing64]

Using Firefox, after exiting full-screen from the Scratchpad UI, using Esc key, on top editor: the browser's focus is locked to the RHS side menu hide/show toggler.

You cannot type any code or click anything until you refresh the page. (The focus is being reset to that element after doing anything?)

Here is a screenshot of the element being focused: