If the Minecraft window is small enough so that a scrollable menu displays its scroll bar, the tooltip from the first option of the eighth row of the menu appears when hovering over the left half of the top of the screen.
(r/oddlyspecific)

How to reproduce:

1. Toggle fullscreen off if you have it on.
2. Change the window resolution to 854x480 and GUI scale to 2 (example numbers, but these are what I used).
3. Go to the chat settings menu or the accessibility menu.
4. Confirm that the scroll bar is displayed. If not, go back to step 2 and change the setup.
5. Hover over the top of the screen, above the first column of buttons. You should see the Hide Matched Names tooltip (if in Chat Settings) or the Darkness Pulsing tooltip (if in the accessibility menu). If not, exit that menu and retry.

What I expected to happen was:

Nothing.

What actually happened was:

The Hide Matched Names/Darkness Pulsing tooltip appeared.

Discovered while testing MC-249063.