I set my player's health to 100 but in the debug it says its 0 and its not affected by code

I set my player’s health to 100 but in the debug it says its 0 and its not affected by code

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

public class GameManager : MonoBehaviour
{
    public static GameManager gameManager { get; private set; }

    public UnitHealth _playerHealth = new UnitHealth(100, 100);

    void Awake()
    {
        if (gameManager != null && gameManager != this)
        {
            Destroy(this);
        }
        else
        {
            gameManager = this;
        }
    }
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerBehaviour : MonoBehaviour
{
    void Start()
    {

    }

    void Update()
    {
        if (Input.GetButtonDown("Fire1"))
        {
            PlayerTakeDmg(20);
            Debug.Log(GameManager.gameManager._playerHealth.Health);
        }
        if (Input.GetButtonDown("Fire2"))
        {
            PlayerHeal(20);
            Debug.Log(GameManager.gameManager._playerHealth.Health);
        }
    }

    private void PlayerTakeDmg(int dmg)
    {
        GameManager.gameManager._playerHealth.DmgUnit(dmg);
    }
    private void PlayerHeal(int healing)
    {
        GameManager.gameManager._playerHealth.HealUnit(healing);
    }

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

public class UnitHealth : MonoBehaviour
{
    // Fields
    int _currentHealth;
    int _currentMaxHealth;


    // Properties
    public int Health
    {
        get
        {
            return _currentHealth;
        }
        set
        {
            _currentHealth = value;
        }
    }

    // Properties
    public int MaxHealth
    {
        get
        {
            return _currentMaxHealth;
        }
        set
        {
            _currentMaxHealth = value;
        }
    }

    //Constructor
    public UnitHealth(int health, int maxhealth)
    {
        _currentHealth = health;
        _currentMaxHealth = maxhealth;
    }

    //methods
    public void DmgUnit(int dmgAmount)
    {
        if (_currentHealth > 0)
        {
            _currentHealth -= dmgAmount;
        }
    }

    public void HealUnit(int healAmount)
    {
        if (_currentHealth < _currentMaxHealth)
        {
            _currentHealth += healAmount;
        }
        if (_currentHealth > _currentMaxHealth)
        {
            _currentHealth = _currentMaxHealth;
        }
    }
}

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