Admin access and Traffic usage

In the past I was able to connect to my router  (Sage Com FAST 5688W) via I.P as an admin and control all aspects of the device. I can no longer do that? Is there a different approach now?

Trying to determine how much data each device is using that is connected to the router.

Even the phone app does not show the meter.

Any help would be appreciated.

Gracias