While working on my second character for the expansion I was doing the bonus objective in Ardenweald named: Tranquil Pools. Once hitting 100% of the bar, the objective greyed out and isn’t completing. It didn’t show another objective like some do for the “boss” or event of the objective.
Edit: I have tried logging out in the zone and logging back on and didn’t get the complete. People have had some success with this method.