Were you able to diagnose this? I'm having the exact same issue - somehow Network Monitoring & Testing used over 800 gb of data this month without any change in behavior from my household. Support guided my to reset my password in case someone is using our wifi, but weren't able to provide any information about what this category is so that we can prevent overages in the future.
No good solution yet-- sorry you're having the same problem. I did turn on traffic monitoring on my wifi router (not a Cox one), so I will be able to tell in the future at least what machine is eating the bandwidth. But so far haven't seen anything out of the ordinary. I'll let you know if I figure it out.
Thank you for looking into this! Have you learned anything new?
We're experiencing the same abnormal "Network Management and Testing" spike with no change in devices or internet behavior.
Cox support was not helpful when we reached out.
