How to fix model with colliders ignoring physics/collision

enter image description hereProblem: Imported model with Rigidbody and (later added) capsule collider ignores physics and collision with terrain, while other models with colliders work as intended.

Summary: I’m working with the robot kyle model/rigging free asset from the unity asset store. I added an animator controller with idle, walk, run, and jump animations and a simple script for movement. No custom physics scripts attached. I have a ball in the scene with a sphere collider and it works as intended with terrain collision and gravity and projectile motion.