Mac: Tab title tooltips appear over web content and other windows

[MrEricSir]

On my Mac running Sierra with Firefox 66 (and previous versions of FF) the tabcenter-redux tab title tooltips appear on top of not only web content in Firefox, but on top of other Windows when Firefox is not in focus.

So far the only way I've found to make the tooltips disappear is to hover over an empty area in the Firefox sidebar, but this isn't a very satisfying workaround.

[haarp]

Can confirm, this is happening on Linux too. Super extremely annoying when dealing with multiple windows.

Reproduction:

• Move mouse to tab
• Move mouse to another unrelated window before the tab tooltip appears
• Tab tooltip will appear regardless and stick around until Firefox window or tooltip (which counts as part of the Firefox window) is hovered over again

[haarp]

Seems to be a general Firefox bug, I'm getting the same with the bookmarks sidebar.

https://bugzilla.mozilla.org/show_bug.cgi?id=1569439