Bugged quests

I just turned in the 3rd artifact to Oleff, but the quest updated into saying I gave him two artifacts when I gave him all three. Now the quest is stuck as unfinished. I got the reward, sure, but I may have missed out on some XP for the quest not being marked finished. Even if I didn’t, I want it out of my journal.

Is there a command or something to fix this?

Edit: Changed the title because there’s another bug. In Act 1 (OC by the way, shoulda mentioned it), I’m supposed to encounter 4 assassin groups, one in each district. However, I never encountered the Peninsula group, encountered the Blacklake group twice, and the Docks group spawned after I stepped on the trigger for the umpteenth time.

What’s worse is that the Blacklake group gave me 2 different notes, but the Docks group gave me a note I already got. So now this questline is technically unfinished, and I wanna finish it too.

Edit #2: I’ve consulted with 2 lists for item codes, and there’re only 3 Anonymous Letters listed, all three of which I’ve already gotten. What’s more, I’ve only found one spot on the Internet where it says there are 4 encounters, and every other place that had info only mentioned 3 encounters and 3 letters.

From this, I’m concluding that there were 4 encounters planned but one of them was cut out with bugs left on the triggers. In short, that would mean I’m only getting 3 letters, not 4, ergo the questline is finished.

Would rather some help confirming this, though.

I also still need help with the Tyr quest. Dunno how to handle it except by spawning one of the artifacts and hoping it fixes itself.

Edit #3: Tried spawning Halueth’s Rusted Armor and Jacob’s Quill. No conversation prompts/options appeared. I guess I can only use console commands or something to get rid of the quest entry.