On Mac, in fullscreen, with hide toolbars on, moving the pointer to the top of the screen to reveal what’s hidden pushes the page down (or down and right with vertical tabs or the sidebar visible), as opposed to revealing an overlay on top of the page.
They fixed the same bug for fullscreen with hide toolbars off, but on a MacBook with a notch, you don’t gain any screen real estate in fullscreen with hide toolbars off.
Makes fullscreen not worth using.
And while it’s a relatively minor issue, fullscreen adds a blank title bar, shifting some toolbar buttons and the address bar left: