Big thanks to Flomsen, Pionara, Monsterf9, Sjarrel and all others!
I updated my F920BT !
before the update, it was Version 5.0 from 2013 and after the update, it was Version 6.0.
As I want to update the bluetooth firmware, it says, that the installed version is 3.32 and the new Version 3.32, too.
Is this correct with Version 6.0 and BT 3.32?