I’m playing on PS5.
The teal exclamation point indicating a new quest will not go away on the Quests tab, even though there are no new unread quests.
I’m not sure when this started occurring, but I think it was some time during the Oxenefordscire arc, or maybe when adding buildings to my settlement. It happened around the time Valka showed up. I have not yet built her house. Also around that time, I had a quest from Leda expire and got a “quest completed” notification. (Noting this as a potential cause.)
I have tried restarting the game, and the issue persists.