Social Blocking

I have set up a rule to block Social during school hours. This seems to mostly be working, however, I notice some domains are still getting through, even though Firewalla has correctly categorised them as Social. For example, the domain app.snapchat.com was blocked, but the domain app-analytics-v2.snapchat.com (which Firewalla has categorised as Social) was not blocked. Similarly, most TikTok domains were blocked, but a few such as frontier.tiktokv.com (correctly categorised as Social) were not blocked.

I would have thought that when Social block is activated, any domain that Firewalla has categorised as Social would get blocked. Why are some still going through?

I can't actually check whether the block is working overall as I am not home to see it.