Hi, Christian. Can you please show us your cable connections? both power cable and communication cable connections.
Also confirm if your communication cable (master battery to Cerbo GX) has correct pin configuration,
battery side:
CAN H : pin 4
CAN L : pin 5
Inverter side:
CAN H : pin 7
CAN L : pin 8 Connect Pins : 4–>7 & 5–>8
I build the CAN Cable by my self, and I testet the Pin as you described. Otherwise the Communication wouldn’t work, or?
On the 48V DC side I have 70mm2 cables from each Victron Multi RS to the victron lynx distributor with 200A Fues. And from there also 70mm2 to the Pytes R-Box also fueled with 200A