My Objects are falling through the floor..

Hi, I'm making a 1:1 running game using unity. but if I start, the player object is falling through the floor. The floor and Player object have their colliders and rigid bodies. And I checked the gravity.. they're not triggers too. Also, the player is not kinematic. I don't know why it happened...

here's my code.

 public class Player : NetworkBehaviour {
     public Rigidbody rbody;
 
     private float inputH;
     private float inputV;
     
     void Start () {
         rbody = GetComponent<Rigidbody>();
         
     }
     
     void Update ()
     {
         if(!isLocalPlayer)
         {
             return;
         }
 
         inputH = Input.GetAxis("Horizontal");
         inputV = Input.GetAxis("Vertical");
 
         float moveX = inputH * 500f * Time.deltaTime;
         float moveY = 0f;
     float moveZ = inputV * 1000f * Time.deltaTime;
 
         rbody.velocity = new Vector3(moveX, moveY, moveZ);
     }
 }
 
 

my english is not really good, so you may can't understand my writing.. if so, tell me. i'll wait for your answer! :)