Camera rotation locking to center at lower framerates

Ok this problem is hard to explain, but ill do my best. First here is the code for my playerController:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerController : MonoBehaviour
{
    [SerializeField] private GameObject _camera;
    private Vector3 _playerVelocity;
    private float _playerRotation = 0;
    private Ray _ray;
    private RaycastHit _hit;
    private int _grounded = 0;
    private void Update()
    {
        _playerVelocity = new Vector3(0, 0, 0);
        if (Input.GetKey("w"))
        {
            _playerVelocity += new Vector3(0, 0, 1);
        }
        if (Input.GetKey("a"))
        {
            _playerVelocity += new Vector3(-1, 0, 0);
        }
        if (Input.GetKey("s"))
        {
            _playerVelocity += new Vector3(0, 0, -1);
        }
        if (Input.GetKey("d"))
        {
            _playerVelocity += new Vector3(1, 0, 0);
        }
        if (Input.GetKey("space") && _grounded != 0)
        {
            _playerVelocity += new Vector3(0, 5, 0);
        }
        gameObject.transform.Rotate(new Vector3(0, Input.GetAxis("Mouse X") * 3, 0));
        _playerRotation = Mathf.Clamp(_playerRotation - Input.GetAxis("Mouse Y") * 3, -90, 80);
        _camera.transform.eulerAngles = new Vector3(_playerRotation, gameObject.transform.eulerAngles.y, gameObject.transform.eulerAngles.z);
    }
    private void FixedUpdate()
    {
        gameObject.GetComponent<Rigidbody>().AddRelativeForce(_playerVelocity * 20);
        _ray = new Ray(gameObject.transform.position, Vector3.down);
        if (Physics.Raycast(_ray, out _hit, 1.1f))
        {
            if (_hit.transform.gameObject.tag == "Ground"){
                _grounded = 10;
            }
            else
            {
                if (_grounded > 0)
                {
                    _grounded -= 1;
                }
            }
        }
        else
        {
            if (_grounded > 0)
            {
                _grounded -= 1;
            }
        }
    }
}

The code works absolutely fine normally, i can move, jump, look left right up and down, however when i lower my framerate (i remove my charger) I can no longer rotate horizontally with my mouse.

to be more specific, its not that the horizontal rotation just doesnt work, the camera does rotate in the direction i am trying, and the Mouse X variables are fine (i used print()) but when i look in a direction, some kind of force pulls the camera back to the center, basically undoing my rotation.

if this didnt make too much sense, here is a video, though its hard to demonstrate.

Fixed! At last!

For anyone else having this VERY specific problem, the solution was to just turn off Interpolate in the rigidbody!