Apparently some sensors don't like icons. Lame.

sensors/entertainment.yaml

@@ -20,7 +20,6 @@
   sensors:
     basement_tv_current_app:
       friendly_name: 'Basement TV Current App'
-      icon: mdi:television-play
       value_template: >-
         {% if is_state('media_player.basement_tv','off') %}
           Off
@@ -29,7 +28,6 @@
         {% endif %}
     living_room_tv_current_app:
       friendly_name: 'Living Room TV Current App'
-      icon: mdi:television-play
       value_template: >-
         {% if is_state('media_player.living_room_tv','off') %}
           Off
@@ -38,7 +36,6 @@
         {% endif %}
     master_bedroom_tv_current_app:
       friendly_name: 'Master Bedroom TV Current App'
-      icon: mdi:television-play
       value_template: >-
         {% if is_state('media_player.master_bedroom_firetv','off') %}
           Off