Physics Ragdoll Problem

So basically, I am making tower defense game. Inside the game, the players can buy unique bases to aid them. However, the problem is that when the boss walks through the base, it also trips over some of it’s towers. It makes them ragdoll into the ground and sometimes it ragdolls them through the ground and they fall into the void. For both the base and boss, each of their part’s CanCollide is set to false. And I even made collision groups for them but it still failed to work. I need some help!