Dashboard Icons not Changeing

I have tried to use different icons on my dashboards, but having problems changing them from the default, for example

widget_type: switch
title: Dining
title2: Room Lamp
title_style: “font-size: 100%;”
icon on: mdi-lamp
icon off: mdi-lamp
entity: switch.dining_room_lamp

All this shows is the default, Bulb icon.

I have tried use_hass_icon: 1 or 0 and still the required icon is not displayed.

Any suggestions what I am doing wrong?

if it still shows the bulb, its probably cashed.
if you put in an icon with a failure you would get no icon.

clear your cache in your browser and clear all subdirs in the directory conf/compiled