@drewex 

Hi, traffic monitor displays the traffic usage of a device in the past 10 minutes or that of all devices in the past 10 minutes/24 hours/7 days, and you could use it as a reference. And disabling NAT boost is okay.

In addition, since your data plan of your SIM card is limited, you could also consider using the data usage settings, which enable you to monitor and manage the amount of data consumed by the router. These settings allow you to monitor data usage, set usage limits, and receive notifications when certain thresholds are reached.

By utilizing data usage settings, you can manage your data consumption and avoid exceeding your plan's data limit.