Still encountering the disappearing tooltips bug. It's been years! Maybe this tid-bit will help: I hover over one tooltip in the research menu and it does not show. I move the mouse over a different research and then back to the first one and it suddenly appears again. However, if I mouse over a third research and back to the first one it is broken again and does not show the details.

It also is more often present when I play a multiplayer match with a specific person present. Anytime that individual is in the game I encounter the bug in some capacity.

A while back I tried to find a pattern when this bug happened. This is what I found out.

I seem to get this bug more on my laptop, which has low performance.  I wonder if it's possible that it's caused by a race condition, some kind fo asynchronous thread in the UI, or something loading out of order because of timing issues?  So with latency it's easier to reproduce?  I hope the game will even be playable on my laptop because of this.