State timeline: State 0.500 in binary sensor

Hi experts,
I am trying to set up a state timeline in Grafana for a binary_sensor and have noticed that in this sensor there seems to be not only the state “0” and “1” but also “0.500”. This was not the case with other binary_sensors.
Can anyone tell me why there is a third state here and how to handle it?

Thanks in advance for every hint!

Best regards
Rado

Hi Everyone,
Has been solved. After trying hundreds of times, I replaced mean with top(1) and now it works.
Best regards
Rado