The Steam description for the achievement "The Science Guy" is "Meet Zhirov in his lab.",
while the in-game description is simply "Find Zhirov.", which seems outdated.
Correct, though not a bug. The in-game description cannot be updated until a release is made, since it's stored within the game itself. This does not happen until Beta 15 (it's a new more specific description), but I generally update necessary Steam achievement descriptions before the releases actually happen because they are handled separately via Steam's own backend interface and people can benefit from that knowledge immediately without an actual update happening.
Whoops, i thought i remembered it being different even before Beta 14. Sorry!
Yeah I always make the changes simultaneously in the game data and on Steam, but the latter appears immediately whereas the former just happens whenever it goes out. That was a pretty new one I updated specifically in response to a conversation I saw not too long ago on Discord, just to make it clearer.
I actually only started doing this over the past year though--before I would always wait until the release actually happened then simultaneously update everything on the Steam side, precisely because I wanted to avoid inconsistency and people thinking there's something wrong, as happened here... but anyway I wanted to try doing it a new way since this has its advantages as well.