I spent weeks leveling each class to 70 and farming for the etherial weapons, got all 21 and somehow didn’t get the achievement showing up now that I’m logging in for season 25 … what’s going on?
I’m pretty miffed that I spent all that time for the achievement and now can’t use the transmog in the new seaon!
Hi:
There’s a lengthy topic about that issue on Bug Report forum, with a reply by Blizzard here:
That being said… it’s been 6 days since that reply and no update since. 
Thanks Boubou, I had not found that with my searches, probably cause I can’t spell ethereal
I’m happy that I could help you.
Best of luck in your games… and with this issue.
I’m gonna be super annoying and revive this dead post, because this issue still exist and has still not been fixed. I have previously made 2 tickets to support about this issue, with the last one being 6 months ago and was planning to make a new one today, but it seems the only issues you can report are now perfomance issues and crashes. Last time I made a ticket about this I was told that the develepors were aware of the issue, but then how come it hasn’t been resolved yet? >:(