Non-functional Group config ignored by Check Configuration button

[hugalafutro]

Not sure if this is an issue or expected behaviour, but I just spent half an hour trying to figure out why one of my groups is not showing in dashboard, turns out I forgot the entities: line, so the group in question looked like this:

tablet:
  name: Tablet
    - sensor.lenovo_tb_x704l_battery_level
    - sensor.lenovo_tb_x704l_battery_state
    - sensor.lenovo_tb_x704l_wifi_connection
    - sensor.lenovo_tb_x704l_geocoded_location
    - sensor.lenovo_tb_x704l_last_reboot

however pressing Check Configuration in the HA restart screen said config is valid, but the group did not appear after reload nor restart.