Hi,
I believe the space between the text and the edge of the control is padding, and between controls is margin.
I tried settings on the layout, and on each button, still left a gap between them
(even tried lay.SetChildMargins(0,0,0,0,0), and but1.Method("setPadding","int,int,int,int",0,0,0,0) - no difference).
I suspect this is built into Android (WebView).
Until the Technical team can give a definitive answer you could try
using Text boxes with SetBackColor and SetMargins - it works in my layouts
(you probably need to use OnTouchDown or OnTouchUp instead of OnTouch because Text boxes will call OnTouch for both down and up touches).
I've only just got Premium, so I know very little about Material UI (MUI), perhaps some-one could try that.
Regards, ah