I completed the campaign on my main paladin, I did all the sides quests on another character. I have done all the quests available, but I am still missing multiple achievements in multiple zones on that character. I can log onto my paladin and see the quests i9m missing and do them and every time it says it’s been completed already. In Hallowfall I’m missing the side quest achievement “Crushing Depths”… and in Azj Kahet I’m Missing side quest achievements “Pawns and Puppetry” “Mr Sunflowers Therapy” “Melody of Madness” “Subterfuge In Silk” and lastly “Grieve and Weave”
For the ones from Azh’ Kahet go into the city of threads and look at your mini map while in the city and you should see those quests. I don’t remember being able to see them on the mini map outside of the city.
For the crushing depths side quests. Try killing Kobyss Shadeshaper in hollowfell as those can drop an item to start that chain.
there are some side quest that cant be completed if you dont have some progress ON THAT CHARACTER on main story… as someone who have completed all the loremaster achievs i had several issues with this…
TBH what i did was using the BtWQuest addon and wowhead comments… is the only help i can provide 