Unloading the 12V Hecck battery, long rides with the E-Tense is a nuisance!

Hello Together On a longer journey to Italy, 2500 km, two errors occurred during the return journey: 1. The yellow engine sign lights constantly. can not reset. 2. fault electric drive. In Ticino, in front of the Gotthard, I called the hotline. If the petrol engine runs normally, I should drive home and bring the car to my workshop. The report from customer service reads: On long journeys the small 12V battery in the rear discharges, and the electrical system The error can only be deleted by the program in the workshop. If the errors are there, the loading of the main battery is useless. The electrical system is switched off. There is no solution for the time being. An update with the latest data has probably been made. But the workshop manager does not know if the problem is solved. Who knows more?