Any idea why this happen?

Questions & Answers
1

I’m new to Unity and I still don’t understand many things, any idea why this is happening?

3

I think the issue is that you’re adding transform.position.y to the move vector. and I am assuming the y is not zero when the character steps on something. In which case your finalMoveVector becomes (0,1,0) when normalized, and that causes your character to fly up.

2

Sure! there you go

using System;
using System.Collections;
using System.Collections.Generic;
using Cinemachine;
using UnityEngine;
using UnityEngine.InputSystem;

public class PlayerController : MonoBehaviour
{
    [SerializeField] private InputActionReference movement;
    [SerializeField] private float moveSpeed = 7f;
    public float speedMultiplier = 1f;

    private Animator characterAnimator;
    private CinemachineVirtualCamera virtualCamera;
    private bool canRun;

    private void Awake()
    {
        virtualCamera = GameObject.FindObjectOfType<CinemachineVirtualCamera>();
        characterAnimator = GetComponentInChildren<Animator>();
    }

    private void Start()
    {
        virtualCamera.Follow = this.transform;
    }

    private void Update()
    {
        Vector2 moveVector = movement.action.ReadValue<Vector2>();
        Vector3 finalMoveVector = new Vector3(moveVector.x, transform.position.y, moveVector.y);
        finalMoveVector.Normalize();
        
        if (finalMoveVector != Vector3.zero)
        {
            transform.forward = Vector3.Lerp(transform.forward, finalMoveVector, Time.deltaTime * 17f);
            transform.position += (finalMoveVector * (moveSpeed * speedMultiplier)) * Time.deltaTime;
            
            characterAnimator.SetBool("IsWalking", true);
        }
        else
        {
            characterAnimator.SetBool("IsWalking", false);
        }
    }
}

The character has this structure:
image
An empty object and then the actual visual part of the character

Also the rigidbody and the collider are in the “MaleCharacterPBR”, may that be the problem?