The modem shows the same data as Telstra - and it also shows how much I have left on my data plan, so either it is sourcing it’s data from Telstra or vice versa. It is a 5g modem and has connection info directly on the modem, which includes what devices are logged in. I did find my old iPad was still plugged in and connected, but I turned that off a few days ago with no change, and there are no other unexplained devices.

I initially assumed I had an app or something chewing through extra data (like that time I installed the official Reddit app) but there are no apps showing as using much data and after going through any settings I can find to limit things like auto-play video, changing browsers to Firefox to block adds and trying to minimise time spent in pointless scrolling the data use has gone up not down. My tablet is calculating my usage as generally around 40-60gb a month, and probably close to half of that would be on the work wi-fi. But telstra has me at about 70gb and I can’t figure out why.

Obviously it is a low data amount anyway so it’s not really a major financial issue, but it is bugging me that it does not match up.