Tab Selection Highlighting Not Working On Tree Tabs

How to reproduce:

Simply try to select multiple tabs in vertical/tree mode such as using Ctrl-LeftClick or multiple at a time using Ctrl+Shift+LeftClick as one might in horizontal mode on any browser.

Only the last selected tab will be highlighted which one might think means only one is selected but if you try something like Ctrl+W to close tabs it will close all the ones selected as expected.

Essentially this is a graphic bug where selected tabs in vertical/tree mode are not highlighted properly.

I’m on Windows 10 but this could be happening on other operating systems.