History stats shows "undefined" when it is correctly calculated

[VDRainer]

How to make Sensor show minutes or hours instead of 0.52 hours = 30 minutes

At the moment, the history_stats senor has an attribute value that shows days, hours, minutes. [20220502_224729] This ‘value’ will be removed in the upcoming 2022.5 release to avoid to many attribute records in the database. [20220502_224708] The device_class ‘duration’ shows the state in a human readable format in the frontend. [20220502_224811]