Q1 : I’ve completed few ones after I tried the methods (100% sure). Achievement notification correctly poped up, but season journey screen was still blank.
I may also have completed some ones before the method, but can’t be affirmative as it was few days ago.
Q2 : Yes, the achievement notification poped up again (and I’m sure it poped up also the very first time). The objective was “Complete a Set Dungeon” and/or “Master a Set Dungeon”, as I think I’ve completed both simultaneously.
I do not believe it could be a simple delay in the update of achievements, for this particular case.
Please also note that I’ve posted a support request ticket on the EU site, and after few days telling me that I should follow methods described in this current thread, I just had an interesting answer this morning.
I can’t link you the answer of the game master as it is inside my ticket (and in french language), but he said me that (I’ve just ‘google trad’ it) :
Thanks to all the reports we received, the developers ended up confirming that for some players the problem was indeed related to a bug in game.
They have not yet managed to reproduce the situation that created the bug at the origin but they are working in all cases to correct this