Nextra's Erricson modem not working with UPS

Hi, so i have a Nextra connection in which the fiber comes into an ericsson modem and then an ethernet cable to my wireless modem.

Due to frequent power cuts, i bought a UPS. The model number is iBall - generation i

The problem i am facing is that during a power cut, the wireless option stays on as it is getting power from the UPS but the ericsson modem turns off during the power cut, but it is still connected to the same UPS. There are no other devices connected to the UPS.

Only the Wireless modem and the ericsson modem are connected to the iBall UPS, but the ericsson modem is not able to draw power from the UPS

UPS isn't the best option for powering modems as it outputs AC by converting DC from battery with an inverter. Which then again has to be converted back to DC by the modem power adapter.

Anyways, if the Wifi router uses same adapter connector, try powering the modem with that.

the wifi router is a 2 pin plug and modem a three pin plug. i have put the modem in different power sockets of the UPS but still the same thing.

I meant the other end, the connector you plug into the modem.

Try plugging your wifi router power connector to your modem.

Did not help. I think the issue seems to be something related to the stuff mentioned in the https://blog.tripplite.com/pure-sine-wave-vs-modified-sine-wave-explained/

What all 600 VA UPS support Sine Wave?