Rigidbody spins out of control

So I'm building a third-person character, say 3D platformer. I'm using a rigidbody and capsule collider. My problem is that whenever I jump, if I hit a corner of a cube, the rigidbody gets stuck to it's edge. And worse yet, it sometimes continues moving along the edge like it's locked to it. And even worse is if it does get dislodged from the edge, upon landing on the ground it starts spinning out of control. But weirdly enough I can kind of slow down the rotation using the controls, if I let go, it goes right back to the same spin speed. This seems to happen whenever the edge meets the rounded portion of the capsule collider. If it hits the flat surface it acts properly.

My left-right controls are supposed to rotate the player, with up and down being the forward or reverse velocities. Anyone else run into this, and how they might have solved it?

Here's some relevant code (I believe)

 //Here's the inputMovement line.
 inputMovement.Set(Input.GetAxis("Horizontal") * calculatedSpeed * 2f, 0f, Input.GetAxis("Vertical") * calculatedSpeed);
 
 public virtual void FixedUpdate() {
 
             curPosition = transform.position;
             curRotation = transform.rotation;
     
             forwardVector = transform.forward;
             forwardVector.y = 0f;
             forwardVector.Normalize();
     
             CheckGrounded();
     
             if(grounded) {
     
                 targetVelocity = forwardVector * inputMovement.z;
                 targetRotation = curRotation * Quaternion.AngleAxis(inputMovement.x, Vector3.up);
     
                 if(doJump) {
                     doJump = false;
                     isJumping = true;
                     rigidBody.AddForce(transform.up * calculatedJump, ForceMode.Impulse);
                     Debug.Log("Did jump!");
                 } else if(isJumping)
                     isJumping = false;
             }
     
             setVelocity = Vector3.Lerp(rigidBody.velocity, targetVelocity, Time.fixedDeltaTime * 5f);
             setVelocity.y = rigidBody.velocity.y;
             rigidBody.velocity = setVelocity;
             rigidBody.rotation = Quaternion.Lerp(rigidBody.rotation, targetRotation, Time.fixedDeltaTime * 5f);
         }