Diagonal movement causing player to run (counting as a second tap for double tap running)

currently I have a double tap system enabled for running however when I move diagonally it's counting the key press as a tap and I don't want that... I have tried a few things but to no avail...

So if I double tap any 4 directions works fine and can run diagonally, but if I'm walking then move diagonally for whatever reason it then goes into it's running state.

  if (Input.GetKeyDown(KeyCode.DownArrow) || Input.GetKeyDown(KeyCode.LeftArrow) || Input.GetKeyDown(KeyCode.RightArrow) || Input.GetKeyDown(KeyCode.UpArrow))
             {
                 // double tap running
                 if (buttonrefresh >= 0 && buttontap == 1)
                 {
                     mv_Model.speed = 9;
                 }
                 else
                 {
                     buttonrefresh = 0.5;
                     buttontap += 1;
                 }
             }
             else if (Input.anyKey == false)
             {
                 // if a button hasn't been pressed reset the tap count
                 if (buttonrefresh > 0)
                 {
                     buttonrefresh -= 1 * Time.deltaTime;
                 }
                 else
                 {
                     mv_Model.speed = oldspeed;
                     buttontap = 0;
                 }
             }
         Debug.Log(buttonrefresh);
         // don't allow diagonal taps
         if (isMoving == true)
         {
             buttonrefresh -= 1 * Time.deltaTime;
         }
         if (can_move)
         {
             if (Input.GetKey(KeyCode.DownArrow))
             {
                 newDir.y = -1;
                 isMoving = true;
             }
             if (Input.GetKey(KeyCode.LeftArrow))
             {
                 newDir.x = -1;
                 isMoving = true;
             }
             if (Input.GetKey(KeyCode.RightArrow))
             {
                 newDir.x = 1;
                 isMoving = true;
             }
             if (Input.GetKey(KeyCode.UpArrow))
             {
                 newDir.y = 1;
                 isMoving = true;
             }
         } else {
             mv_Model.speed = oldspeed;
             buttontap = 0;
         }

Any help is appreciated.

Edit: Solved by giving each direction dedicated variables.

         // double tap dash
         // down
         if (Input.GetKeyDown(KeyCode.DownArrow))
         {
             // double tap running
             if (buttonrefreshd >= 0 && buttontapd == 1)
             {
                 mv_Model.speed = 9;
             }
             else
             {
                 buttonrefreshd = 0.5;
                 buttontapd += 1;
             }
         }
         else if (Input.anyKey == false)
         {
             // if a button hasn't been pressed reset the tap count
             if (buttonrefreshd > 0)
             {
                 buttonrefreshd -= 1 * Time.deltaTime;
             }
             else
             {
                 mv_Model.speed = oldspeed;
                 buttontapd = 0;
             }
         }
         // left
         if (Input.GetKeyDown(KeyCode.LeftArrow))
         {
             // double tap running
             if (buttonrefreshl >= 0 && buttontapl == 1)
             {
                 mv_Model.speed = 9;
             }
             else
             {
                 buttonrefreshl = 0.5;
                 buttontapl += 1;
             }
         }
         else if (Input.anyKey == false)
         {
             // if a button hasn't been pressed reset the tap count
             if (buttonrefreshl > 0)
             {
                 buttonrefreshl -= 1 * Time.deltaTime;
             }
             else
             {
                 mv_Model.speed = oldspeed;
                 buttontapl = 0;
                 isRunning = false;
             }
         }
         // right
         if (Input.GetKeyDown(KeyCode.RightArrow))
         {
             // double tap running
             if (buttonrefreshr >= 0 && buttontapr == 1)
             {
                 mv_Model.speed = 9;
             }
             else
             {
                 buttonrefreshr = 0.5;
                 buttontapr += 1;
             }
         }
         else if (Input.anyKey == false)
         {
             // if a button hasn't been pressed reset the tap count
             if (buttonrefreshr > 0)
             {
                 buttonrefreshr -= 1 * Time.deltaTime;
             }
             else
             {
                 mv_Model.speed = oldspeed;
                 buttontapr = 0;
                 isRunning = false;
             }
         }
         // up
         if (Input.GetKeyDown(KeyCode.UpArrow))
         {
             // double tap running
             if (buttonrefreshu >= 0 && buttontapu == 1)
             {
                 mv_Model.speed = 9;
             }
             else
             {
                 buttonrefreshu = 0.5;
                 buttontapu += 1;
             }
         }
         else if (Input.anyKey == false)
         {
             // if a button hasn't been pressed reset the tap count
             if (buttonrefreshu > 0)
             {
                 buttonrefreshu -= 1 * Time.deltaTime;
             }
             else
             {
                 mv_Model.speed = oldspeed;
                 buttontapu = 0;
                 isRunning = false;
             }
         }
         // don't allow diagonal taps
         if (isMoving == true)
         {
             buttonrefreshd -= 1 * Time.deltaTime;
             buttonrefreshl -= 1 * Time.deltaTime;
             buttonrefreshr -= 1 * Time.deltaTime;
             buttonrefreshu -= 1 * Time.deltaTime;
         }