The Bug:

The "Cancel" button within some realms menus can be deselected using keyboard navigation despite it being the only element within the said menu.

If you're struggling to understand what the problem is, please have a watch of the attached video which will hopefully help clear up any confusion.

MC-265516.mp4

Steps to Reproduce:

1. Navigate to the minecraft realms menu.
2. Click on your realm, join it, and as you're connecting to the realm, constantly press the TAB key.
3. Take note of how the "Cancel" button is selected and unselected as if there was another element that was being focused on your screen.
4. Take note as to whether or not the "Cancel" button within some realms menus can be deselected using keyboard navigation despite it being the only element within the said menu.

Observed Behavior:

The "Cancel" button can be deselected using keyboard navigation despite it being the only element within the said menu.

Expected Behavior:

Since the "Cancel" button is the only button that's on screen, it shouldn't be able to be selected and deselected using keyboard navigation. Once it is selected, it should remain selected if the TAB key is pressed again because no other elements are on screen.