CPL taken not effective

Hello,
This UPS Announces CPL compatible socket on 4 powerline taken not taken over by the battery: It's already a default because if immediate shutdown of the CPL taken, what is a UPS with battery but in addition I found a flow rate
low (orange or red LED) if taken THUS PLC connected to the inverter:
I had to connect the plugs for the wall outlet and the UPS / Battery
after, which indicates that the CPL taken with ETHERNET connection is not supported by the UPS battery in case of power failure.
Yet I chose this model because of the CPL compatibility.
For the rest ie if power failure or current change I see in use.