Bitter Rival Quest Bugged

[MrCampin]

Hey, I've been trying to complete the bitter rivals quest, and it's bugged out. I get the quest and the barrel of Barleybrew Scalder, however, I can't interact with Jarven guarding the barrel. I can right-click on the guarded barrel there and it tells me to get the guard to move, but I can't interact with Jarven even when I have a tankard of Thunder ale.

[Pottu]

Click on the tankard in your inventory.

The GM team.