Unlocking achievements at once?

I dont understand why this happened, probably because i did do these things but it says i unlocked certain achievements at the same time as each other. I'm asking if this is normal because I'm scared something might happen to my account because of this.

 

not exactly normal but it is possible to happen legitimately, so no problems with this

 

problem is tho, is something gonna happen to my account?

 

just said no problems, so no. ur account is fine

 

I have noticed that when I play in offline mode I do not get any achievements until I launch the game in online mode, and then I get a bunch of achievements at once (in the main menu), that could have been what happened.