Fronius + reserva battery, any way to detect calibation process

Yesterday my fronius / reserva went into calibration process.
In practice, battery level is drained down to single digit percentage load.

Without knowing about ongoing calibration process, one would assume some kind of bug.

Hence my question: Is there any option i might have overlooked to detect the ongoing calibration process within OH 5.2.?

Inverter status and error code doen’t change during this period of time, same for battery cell status.
Fronius web page shares more details like: calibartion process, forced load, min SOC reached, ..

The upcoming 5.3.0 release and its milestone builds have a calibration channel on the battery Thing. This was only recently added, so it is no part of 5.2.x though.