Problem when a device is missing

[MrMattn]

Everything worked great for weeks.
I have 2 inverters on my solar system.
1 inverter was off for 2 days.
After switching it back on, no data was received.
Tried various ideas.
Victron integration deleted. Also in HACS.
Reinstalled everything
All devices were found.
.
Today 1 inverter had to be switched off again.
Same problem.
What could be the reason that no data is being received?
The inverter can be seen in the network and the Cerbo also receives all data

[MrMattn]