Was adding a groups widget to one of the dashboards, it seems that the text and icons are not aligned correctly.
( would be nice to switch the lights on and off using the mysensors-2-433mhz gw node)

The button itself works like a charm, just the layout.
(created this issue on github)

https://github.com/mycontroller-org/mycontroller/issues/415

(Solved, use a dashboard layout 4-4-4/12 or bigger, this gives the widget enough space.)