Trouble creating knockback when setting velocity on RigidBody2D

I have a player and enemy game object. When the player touches the enemy the player should be knocked back.

I have the following as my horizontal movement handler:

     void FixedUpdate()
     {
 
         grounded = Physics2D.OverlapCircle(groundCheck.position, groundCheckRadius, whatIsGround);
 
 
         float move = Input.GetAxisRaw("Horizontal");
 
             rb2d.velocity = new Vector2(move * maxSpeed, rb2d.velocity.y);
   
 
     }

As the knockback I have this method on the player class, being called by the enemy:

     void PlayerHit(GameObject enemy)
     {

         Vector2 knockback = transform.position - enemy.transform.position;
         knockback = knockback.normalized;
 
 
         if(knockback.x >= 0)
             rb2d.AddForce(new Vector2(knockbackForce.x, knockbackForce.y), ForceMode2D.Impulse);
         else
             rb2d.AddForce(new Vector2(-knockbackForce.x, knockbackForce.y), ForceMode2D.Impulse);
 
         rb2d.AddForce(knockback, ForceMode2D.Impulse);
 
     }

The problem is that the player gets knocked back only on the vertical axis, not on the horizontal because the velocity is being set to zero on FixedUpdate.

I tried adding a hurt variable in PlayerHit() and set the velocity in FixedUpdate() only if the player is not hurt but that did not help much because I couldn't figure out how to reset the hurt state in a proper way - if reset when grounded it would reset instantly because the player is considered grounded when being touched by an enemy.