This issue began happening after the patch on june 23rd.
It was noticed by me and guild members that the daily quest for the PEN accessory materials sometimes rolled back when you log to a different character after completing it.
It would show completed with red text and all but once you have reloged to the other char it says "1999/2000" and you cant turn it in. The only way to solve this atm seems to be to go back and kill 1 mob to complete the quest again and hope it doesnt bug out next time or not relog between completing the quest and turning it in.
The same thing just happened on my valks awakening quest where you have to kill 50 manes. I killed the 50, ran to soldiers grave and killed a few mobs there then logged back on my main char for a few hours. Once I logged back on the valk I had kill progress on the soldiers grave part still but the mane quest had reverted back to 49/50.
This bug can cost you quite a bit time so I'm hoping for a quick fix.
Bump
Still happening and relog crashes makes it extra annoying as usual.