I was not aware the the battery should be charged to 100% before the first use. It is not mentioned in the manual as far as I know.
The setting in the app that the battery should not be discharged below 10% was never changed. The day before the solar flow worked, but since yesterday the battery is not recognized anymore.
Interesting thing: the extension battery is connected and the SF shows a state of charge at the decide itself, but not in the app.
The pv inputs are also not operational anymore. Input power is permanently 0W