PC [BUG] Missing Steam Achievements

[Lumi]

I found some threads about achievement problems but apparently nothing similar. Sorry, if it's been posted somewhere already.
I'm a long time casual Stardew Valley player and never paid much attention to my steam achievements. I noticed today that I unlocked some achievements in the game but never got them in steam. My most recent achievement was earning 1 Mio coins. I remember getting the achievement, the sound in the night and the pop-up on the next morning.
Since I record videos I often quit the game after starting the next day. Maybe that causes the problem? I've also quit the game after getting the pop-up für 1 Mio coins.
I never used any mods. I play in German, though (which should be unrelated to the problem).

In the picture you can see three of my missing steam achievements. I've circled the corresponding game achievements, because it's all in German.

 

[Odin]

The main reasons for not gettinng Steam achievements would be if you weren't online on Steam at the time you got them or if you hadn't launched the game through Steam that time.

 

[Lumi]

The main reasons for not gettinng Steam achievements would be if you weren't online on Steam at the time you got them or if you hadn't launched the game through Steam that time.

You're right. Sorry, I should have mentioned that. I never play offline and I honestly have no idea how to start a steam game without launching it through steam (e.g. I always get the info "connecting to steam account blablabla" if I start any of my steam games), assuming the latter doesn't happen by accident.

Edit: But I play with a deactivated steam overlay. Though that never caused problems getting achievements in other games and should only prevent the steam pop-ups.