still only showing “offline” 
now it looks like this
- platform: template
sensors:
roomba_bin_state_template:
friendly_name: 'Cleos behållare'
value_template: >-
{% if is_state_attr('states.vacuum.roomba','bin_full', 'true') %}
Full
{% elif is_state_attr('states.vacuum.roomba','bin_full', 'false') %}
OK
{% else %}
Offline
{% endif %}