When Player is facing left, its movement is jittery and the bullet impact is covered by the walls/floor.

My character moves fine when facing right, and the bullet impact is visible over the walls/floor, but when facing left, my character's movement is jittery and the bullet impact is covered by the walls/floor.

Video Link

(It's a bit harder to see the jitter in the recording)

This rotates my player:

 void Update()
 {
     Vector3 gunPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
     if (gunPosition.x < transform.position.x)
     {
         transform.eulerAngles = new Vector3(transform.rotation.x, 180f, transform.rotation.z);
     }
     else
     {
         transform.eulerAngles = new Vector3(transform.rotation.x, 0f, transform.rotation.z);
     }
 }  

This moves my player:

 void Update()
 {
     moveHorizontal = Input.GetAxisRaw("Horizontal");
     moveVertical = Input.GetAxisRaw("Vertical");
 }
 
 void FixedUpdate()
 {
     if (moveHorizontal > 0.1f || moveHorizontal < -0.1f)
     {
         rb2D.AddForce(new Vector2(moveHorizontal * moveSpeed, 0f), ForceMode2D.Impulse);
     }
 
     if (!isJumping && moveVertical > 0.1f)
     {
         rb2D.AddForce(new Vector2(0f, moveVertical * jumpForce), ForceMode2D.Impulse);
     }
 }  

This makes the bullet impact effect when the bullet collides:

 private void OnTriggerEnter2D(Collider2D collision)
 {
     if (collision.gameObject.tag == "Platform")
     {
         Instantiate(impactEffect, transform.position, transform.rotation);
         Destroy(gameObject);
     }
 }