Completed the steps within the dungeon to obtain the root to hand to Keeper Albard, saw the icon back in the main town to hand the item to the Keeper and teleported after leaving the dungeon.
When I teleported to the town the icon disappeared and when I spoke to the keeper, he repeats his lines of dialogue not related to the final step and so I cannot finish the quest.
Tried on both PC and Steam Deck, ended up abandoning the quest and now the quest marker to start it again is nowhere to be seen and the keeper is still in a bugged state repeating the same line as before.