Hi Yannik! Nice game.
I started it four times, and I encountered the rogues only once. I find the room every time, but they are not there. I don't know what I did differently the first time. Can you help?
Spoiler alert!
There are two ways to the surface from the first traboule. One is from the first level down, one is further west passing through a few maze levels. The outlaws should be in that second one. If not, then there is a bug and I will look into it! If you enable from the settings screen cheats, you can get back there quite fasts by teleport (from right click).
I found both, and from the 4 play only once were they in the second place. Exact location: Down-down-west-up-up. There were only regular monsters. Now I will try to delete all game data and restart, and see if it works. I downloaded the game from F-Droid. I can help provide any debug data that you may need.