GUI button doesn't appear on Android

I'm using the following C# code to place a button on screen:

 public void DrawPanoButton()
     {
         float texWidth = m_buttonPano.normal.background.width;
         float texHeight = m_buttonPano.normal.background.height;
 
         float width = texWidth * Screen.width / 1920;
         
         float height = (width / texWidth) * texHeight;
         float y = Screen.height - height;
         float x = Screen.width - width;
         if (GUI.Button (new Rect (x, y, width, height), "", m_buttonPano)) {
             if (this.TappedOnPanoButton != null) {
                 this.TappedOnPanoButton ();
             }
             m_guiInput = true;
         }
     }

It works well on PC, but on Android the button doesn't show up. The interesting part is that if I tap at it's location (bottom right corner) the functionality is preserved, therefore it's only the custom background texture I put on it that doesn't show up..

ALso, here's the code of the attachment of the background texture:

 m_buttonPano = new GUIStyle();
 m_buttonPano.normal.background = Resources.Load("GUI/buttonPano") as Texture2D;
 m_buttonPano.active.background = Resources.Load("GUI/buttonPano") as Texture2D;
 m_buttonPano.onActive.background = Resources.Load("GUI/buttonPano") as Texture2D;