prior to starting this project i had no knowledge that spline mesh components have a collision issue when they are created at runtime, and my procedural generation logic relies completely on this mechanic. For now, in order to fix the lack of collision (rat falling through the floors and walls) of the tunnels, I will have to temporarily deactivate procedural generation. This should be fine for the time being, since the objective is for people to play the game and test out the mechanics of the gameplay / and even if you play the same level a couple of times some actors are still procedurally generated (the enemies and obstacles), so there will be still be some randomization... I apologize for not knowing of this engine limitation at project start and in the meantime I will be studying solutions to this problem.