are you on linux? i know some people having trouble with achievements there. if youre on windows then you could restart the whole thing and delete the save files you have now just in case. if you dont want to do that you can also use the steam achievement unlocker to unlock what the game didnt

Typical "linux support is a half assed afterthought" garbage. Store page claims linux support, devs need to step up and fix this. No, using a third party tool to violate tos and hack your steam account isnt an acceptable workaround.