Terminal velocity on x and y axis is higher than normal when force is applied to both axis simultaneously.

Hello there everyone, I am fairly new to this and I've been trying to find a solution to a problem I have but to no avail. I hope my formatting doesn't make you want to scratch your eyes out.

The terminal velocity of a Rigidbody2D (and acceleration) on the X and Y axis when I use the "add.force" to the X and y axis simultaneously is significantly higher than when I use the "add.force" on each axis individually.

Here's the code:

 void Update()
 {
     if (Input.GetKey("space"))
     {
         yforce = 1f * ymultiplier;
         XYforce = new Vector2(xforce * Time.deltaTime, yforce * Time.deltaTime);
         rbs.AddForce(XYforce, ForceMode2D.Impulse);

     }
     else yforce = 0f;
     XYforce = new Vector2(xforce * Time.deltaTime, yforce * Time.deltaTime);

     if (Input.GetKey("d"))
     {
         xforce = 1f* xmultiplier;
         Debug.Log("X=20");
         XYforce = new Vector2(xforce*Time.deltaTime, yforce * Time.deltaTime);
         rbs.AddForce(XYforce, ForceMode2D.Impulse);

     }
     else if (Input.GetKeyUp("d"))
     {
         xforce = 0f;
         Debug.Log("X=0d");
         XYforce = new Vector2(xforce * Time.deltaTime, yforce * Time.deltaTime);
     }



     if (Input.GetKey("a"))
     {
         xforce = -1f * xmultiplier;
         XYforce = new Vector2(xforce * Time.deltaTime, yforce * Time.deltaTime);
         rbs.AddForce(XYforce, ForceMode2D.Impulse);

     }
     else if (Input.GetKeyUp("a"))
     {
         xforce = 0f;
         Debug.Log("X=0a");
         XYforce = new Vector2(xforce * Time.deltaTime, yforce * Time.deltaTime);
     }

 }

Terminal velocity for X and Y when force is applied to each individually

Terminal velocity for X and Y when force is applied to both simultaneously