why when change object scale not clicking unity

hi, I am creating dynamic scrollView but when change scale of the object became not clicking.

these code of change scale buttons

 float scale = Mathf.Clamp (1/(distance/panOffset)*scaleOffest,0.5f,1f);//scale+0.3f
             pansScale [i].x = Mathf.SmoothStep (instPans[i].transform.localScale.x,scale, scaleSpeed*Time.fixedDeltaTime);
             pansScale [i].y = Mathf.SmoothStep (instPans[i].transform.localScale.y,scale,scaleSpeed*Time.fixedDeltaTime);
         
             instPans [i].transform.localScale = pansScale [i];

when deleting this statement the click on button work fine

 instPans [i].transform.localScale = pansScale [i];

If anyone can help or advise what I should read to make it work. Thanks.