Mac is not monitered

My son's mac is not properly monitored although profile showed his Mac is monitored. What were shown on activities are system time being changed. What does it mean? As i am sure he is browsing a lot but none of the browse activities being shown.

Thanks

My son's mac is not properly monitored although profile showed his Mac is monitored. What were shown on activities are system time being changed. What does it mean? As i am sure he is browsing a lot but none of the browse activities being shown.

Thanks