Calling hass.states.set () resets Atrtibutes?

I set up a listener to MQTT events in a custom component. In this listener, I am calling the state machine via hass.state.set (, ) in order to assign a received value to a status.

During this call, all attributes of the state (friendly_name, unit_of measurment) are removed.

There must be a way to avoid this - any hints for me? Thanks for responding!