Hello, I started a seasonal character and while leveling, I noticed that I was not getting any achievements whatsoever. Then when I hit 70, I hit shift+J and the tracker is empty. Nothing is there.
I see the green leaf next to my name. I created a new character just in case. And nothing. Is my account bugged?
Thank you.
I have the same error with a new season char 
Try this:
Thank you for the response. I have done all you have suggested just now to no avail. Even completely removed the game and battle.net as well.
What I also notice is that all my achievements in general don’t show. On the title area it says “…MISSING!!@”
Very strange…It was fine last season! And all 18 seasons prior to that! Sigh…
@Rika
Sorry to hear that. Those methods worked for many cases, but still few people reported not working for them.
If you tried all methods, don’t forget to try the Extra Remark section. This section was supplied by a player after he tried all methods; another player confirmed his method.
Good Luck ! 
I tried the methods 2/3/4 and worked for me. Thanks.