Hey y'all. I figured I post this since this was mentioned quite a bit on Astats and 100pag. Currently the global unlock percentages and rarest achievements are glitched. While assumptions are made, there is still no official response from Steam.

Here is an active thread talking about this issue on the Steam Discussions.
https://gtm.steamproxy.vip/discussions/forum/0/3175526477749987622/