I am on the “to serve the light” quest s f I have performed the leap of faith. Hytham has brought me back to the other side of the river and the quest objective is saying to follow him. He is currently standing in the boat and will not move. He is stuck there and won’t continue with the quest.
I tried attacking him and it smashed the boat. He swam to the shore but he got stuck there then too.
I am not sure there is a fix for this. When you reload the last autosave you should be back at this exact point except Hytham will be working correctly and will continue with the conversation.