I had to start using a VPN

[usonian]

8. Remote diagnoses are a bitch, but here are some thoughts.

It's the computer, if other devices are accessing the net via the router OK.
And if different browsers are experiencing the same, then it's in the network stack on the computer (or malware)

Malware should be checked for.
Beyond that, do make friends with a computer geek. Said person can run through a whole raft of commands and utilities in short order. Phone and email/text are way too tedious.

I am thinking netstat, traceroute, and others, to judge what's going on with the network.

WARNING! Do not enlist some remote "help desk".

There are ones posing as computer and printer help who will get you to download remote access software, and you are hosed at that point. I think they pose as official support and pay Google or do other SEO to get on the first page.

Now, if the O.S. has some built-in blocking software (i.e. parental controls, p0rn blocker, whatever) then maybe that is problematic.

Kids have been known to do amazing things when given access to Amazon, though I think that Alexa is the usual accomplice)

And that's it.
Good luck.