Gothic Remake Minecrawler's Nest Quest - Lester doesn't show up at the entrance to the mine

Hello,

I believe i stumbled upon a bug that prevents me from progressing in the game.

After giving Ian the cogwheel I'm supposed to meet Lester outside of the mine, by the gate to the mine. Unfortunately he's not there. When I go to the waterfall where the whole gang is supposed to meet, its only Lester there, and when I go near him, he's asking for me to follow him, after which he just stops and does nothing.

I'm guessing that the gang doesn't show up because Lester is not at the entrance to the mine, but at the waterfall, so the game doesn't teleport the NPCs to the waterfall. I tried sleeping for multiple days in different spots but it doesn't help.

Any ideas how to unfuck this mess?