Hello @nwi, after reading the posts I see that replacing the bug does not solve the problem. The firmware being identical on all Internet Boxes (if up to date) and if we consider that the problem is not generalized, or look if we eliminate the problem in the firmware!
1.- The box is connected to the same electrical group as a large electricity consumer (fridge, washing machine, etc.)
2.- The phase which powers the apartment circuit breaker (hence the Box) is a poorly balanced phase (starting the heating, elevator, etc.)
3.- Are there inverters that reinject current into the electrical network (photovoltaic panel).
4.- I would end up with the earthing if there is a good earthing of the sockets.
If the Box is very sensitive to these variations, it would be good to check the points above.
It would also be good to have an idea of where it is located by putting the postal code at the end of its name ex: Ro_CI-1004 gives an idea of the exchange to which we connect and we can also indicate the serial number, model and version of the firmware. This would allow us to make statistics of where the rebooting Boxes are located and also see if it is the same manufacturing series. So no solutions but other avenues to explore.
Greetings @ all