[2D] Can't AddForce to x but y works fine.

Hey guys. Noob problems incoming :D

So I'm working on this 2D Game and wanted to add something like a sliding-movement. Played Titanfall 2 recently and yeah... ^^

I'm stuck at the basic functionality. I want to AddForce to my RigidBody2D Character on the x axis by GetButton.

The function looks basicaly the same like my Jump() function. Only thing is that I switched the variables position to x and set y to 0:

Jump() Function(everything works here. the character gets the force correctly.):

    void Jump()
     {
         if (isGrounded)
         {
             canJumpAgain = true;
             animator.SetTrigger("Jump");
             rigidBody.velocity = new Vector2(rigidBody.velocity.x, 0);
             rigidBody.AddForce(new Vector2(0, jumpSpeed), ForceMode2D.Impulse);
         }
         else if(!isGrounded)
         {
             if (canJumpAgain)
             {
                 animator.SetTrigger("DoubleJump");
                 rigidBody.velocity = new Vector2(rigidBody.velocity.x, 0);
                 rigidBody.AddForce(new Vector2(0, jumpSpeed), ForceMode2D.Impulse);
                 canJumpAgain = false;
             }
         }
     }

Kick() Function(I don't get any force from anywhere.):

     void Kick()
     {
         if (isGrounded)
         {
             rigidBody.AddForce(new Vector2(jumpSpeed, 0), ForceMode2D.Impulse);
             attackController.currentDamage = attackController.normalKickDamage; 
             animator.SetTrigger("Kick");
             attackController.isKicking = true;
         }
         else if (!isGrounded)
         {
             animator.SetTrigger("JumpKick");
             attackController.currentDamage = attackController.critKickDamage;
             attackController.isKicking = true;
         }
     }

Here again the difference between the AddForce on Jump():

 rigidBody.AddForce(new Vector2(0, jumpSpeed), ForceMode2D.Impulse);

and AddForce on Kick():

 rigidBody.AddForce(new Vector2(jumpSpeed, 0), ForceMode2D.Impulse);

I really don't get it.

My GameObject Hierarchy:

• Player1 (the parent containing the previous scripts, Rigidbody2D and a Collider2D for isGrounded purposes)

• -Skin (has an animator controlling the child sprites)

• --Head

• --Body (contains collider set as a trigger for incoming damage)

• --RightArm

• --LeftArm (contains collider set as a trigger for outgoing damage)

• --RightFoot

• --LeftFoot

what could cause a hurdle that don't let my player1 game object move to the side?

isGrounded works fine so no problem here.