Ive tried this on 4 different characters on 2 different servers (Velen and Eonar which are merged). 3 of the characters were 80 and 1 is still leveling. 2 of the max levels completed the quest w/o issues but for the other two the quest keep dropping. The only consistent thing if it is going to happen it does so changing zones and seems to happen every time to an affected character but there no way to tell if a character is affected until it happens.
I posted more details in this other thread before I was directed here.