Blackwall romance bug

So here's my problem: in Skyhold, I've had the talk with Blackwall on the walls, and he said that we couldn't be together, blah blah blah. I came back to talk to him later, and he said something along the lines of "I owe you an explanation, you have to know who I am and what I am, so meet me there and we'll talk".

But, meet him where exactly? It did not add any quest or objective in Skyhold or anywhere on the world. After wandering around I just came back to him to start a conversation, but it jumps to a cinematic of my Inquisitor in her quarters and Blackwall shows up, says thanks for accmponying him to a ruin (what ruin? I never went anywhere) and then after some talk I can start the romance or break up.

It seems there is content missing, the part where I supposedly went with him somewhere, because it doesn't make any sense otherwise.

I tried repairing the game and no missing or damaged file was found also, so it' isn't a download problem.

EDIT: When going back to the Storm Coast, a quest named "Explainations" magically appeared as completed. The description read "there's a Wardens outpost that Blackwall wants to visit, it seems important to him". So the game ate this quest when it should have appeared in the journal and now I missed it completely. A fix would be nice.