I've been leveling a character and pretty much every escort quest I've run into would stop at their destination and nothing would happen.
I'd have to run off till I get the message saying I've moved too far and then run back and wait a bit more and then the quest would finish.
I saw the same issue while I was levelling. But I didn't move away from the escort. I just stood around and waited and the quest would eventually go green. Normally would take about 5mins for the game to recognise the quest was done.