Fabric 1.20.1-0.16.0
Legendary Tooltips 1.4.5

I have an REI addon mod (I think it's Roughly Enough Items that adds it?) that adds a tab listing the different items under a specific item tag. Interestingly, when I hover over an item with a special border color, the border color of the tag will copy that color—but not the design.

See the video below:

I have not tried the mods with just themselves.

Mmmmm seems to be happening with the latest version of Fabric 1.20.1 JEI too, but items in the inventory are affecting both the bookmarks list and ingredients list

Got the same problem here, the tooltips work normally when hovering over items in jei, but dont show up in the normal inventory, although the color changes to the item last hovered above