Better movement script needed? - unity3d

Question

I got an issue that I've been trying to figure out for some time now and still haven't managed. I created a script for movement which besides using the WASD keys also uses two more buttons to go up and down. The thing is - because of the way I added those buttons for some reason no other function regarding position of the player doesn't work well. For example if I put a collider with a simple on trigger transform.position function for the player to hit - the player is placed on that position but then instantly returned back like there was nothing.
Here is my code. I had tons of iterations how this movement can be done. I did it through physics and controller in several ways but nothing helped. Can you guys tell me if it's the code or some hidden Unity synergy that I don't know about?
(this version works around addForce. Regardless, whatever way I make the up and down functions I cannot move the player with script after that.)
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Mov : MonoBehaviour
{
private CharacterController controller;
private Rigidbody Rb;
private Vector3 playerVelocity;
private float playerSpeed =12;
void Start()
{
controller = gameObject.AddComponent<CharacterController>();
Rb = gameObject.GetComponent<Rigidbody>();
}
// Update is called once per frame
void FixedUpdate()
{
Vector3 move = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
Vector3 add =new Vector3 (0, playerSpeed, 0);
controller.Move(move * Time.deltaTime * playerSpeed);
if (Input.GetKey(KeyCode.Mouse1))
{
Rb.AddForce(0, 1200, 0, ForceMode.Acceleration);
}
if (Input.GetKey(KeyCode.Mouse0))
{
Rb.AddForce(0, -1200, 0, ForceMode.Acceleration);
}
}
}

Answer 1

I'm not sure what you mean by "no other function regarding position of the player doesn't work well" but from have you turning "Collision Detection" in your Rigidbody's settings to "Continuous" and "Interpolate" to "Interpolate"? If you don't do so, Unity's collision's may be a bit funky especially if you are going at high speeds.