Source: Steam Community (opens in a new tab)
It looks like there was an issue with achievements, this new update should have that fixed.
Make sure the game is updated, and you might need to "Verify the Installation" from the Steam Game Options.
If they still seem broken, please let me know.
Thank you so much.
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 16209545 · public branch
Steam updated · First observed
Build 16209545 · beta branch
Steam updated · First observed