I setup a 8hrs limit on tether and also a login and out alert sent to my email. It's been working fine until recently that i noticed the time used shown on tether is not reaching the limit. But if i check the email login and out notification time, the login time is well over 10 hours.

I understand that there could be an email delay, but closed to 3 hours off total?? Is it possible?

Also the daily history breakdown is only showing less than 3 hr of usage, is it showing all the site that the devices visited, nothing shown to be on for more than 20 mins, but I know the device spend more than an hour on youtube daily.

I also try rebooting it, but nothing seems to help.

Any idea to correct this would be appreciated!