Hello!
I have same issue on two different instalation.
One of them has CerboGX and 2 Phoenix Inverterers, second one has CerboGX and 2 Quattros. Every device has newest firmware ( 2.92 cerbo and 5.00 multis ). I have tcp communication between plc and cerbos. I use register 33 to switch on and off devices. After switch off and then on every information only from multis are unknown. Every time. To resolve this i have to reboot cerbo few times, sometimes is 2 times, sometimes 5-6. After this measuring and informations from multis are visible. Those problems are from december. Before there were no problems like this. Hope someone have good news how to fix it.
Best regards