K3 Forgotten Outpost

In K3 when doing the FO quest, It seems to bug on me, how to avoid this?

I pick up the scroll after placing the vine, but after that the quest fails to update.

I kill the guard at the gate (often he already is dead by that fase of the game)
I walk to the gate, a popup says "the gate is locked, find some other way in"

But when I cut down the wall on the side, and kill all dark knights inside the quest fails to update.
Hence the cages never unlock, and I wont be able to open them nor have this quest finished.

How to solve this

Did you send a craftsman over to the cages? They won't unlock automatically.