Circle tracks family member's Internet activity throughout the day and displays that information under the Usage section of their profile. Because of the way Circle tracks this activity, there might be a difference between the displayed total time spent online, and the time spent on various categories and platforms.
People often multitask while using the Internet. For example, several tabs could be open in a browser. Circle sees each website or app visited, and categorizes them accordingly. This might cause a discrepancy between the total time spent online and the time spent on a category/platform.
Total time vs. time spent on categories/platforms
Here's an example: Anna's profiles says that she's spent 3 hours online. Below that total, Circle show how long Anna spent on various categories and platforms. Let's see, an hour of Minecraft, an hour of Facebook, an hour of Instagram and 3 hours of Spotify... if you added up all the time Anna spent on various categories and platforms her time online would have exceeded three hours.
Most likely, Anna was multitasking. One minute, maybe she was streaming music while she played games like Minecraft, or perhaps she was looking at social media. In any case, Circle will count all that activity as a single minute online, despite the fact that it will show up in four different places in Usage.
Usage and History
If you have further concerns about a family member's time online, you can expand the categories under Usage or head to the History section of the user's profile, to see a chronological log of a family member's Internet activity.
Missing Usage Data
Are you missing some chunks of data from when you know a family member was active on the Internet? Do you utilize IPv6 on your network? (You should know what this is if you do.) There's a possibility that for you IPv6 is interfering with how Insights tracks this interactivity. Try turning it off and seeing if this helps. See here for more information. If you aren't using IPv6 it's possible that your Circle needs some setup changes or your network is interfering with its ability to track time. Please use the contact info below to contact support if you suspect something is up.