I will add a few more suggestions:
Take a look at everything that is running on the PC via Task Manager, Resource Monitor, and Process Explorer (Microsoft, free). Use all three tools but only one at a time.
https://learn.microsoft.com/en-us/sysinternals/downloads/process-explorer
Objective being to discover some unknown or unexpected process that is running. Just explore and look - no need to rush. Some things will be obvious. Others not so much and they can be researched to discover what they are or may be pretending to be.
Also look in Task Manager > Startup and Task Scheduler for any unrecognized apps, utilities, etc., being launched at start up or later triggered by some other action that occurs.
Confirm that the PC is not sharing anything nor allowing remote access.
Look in the hosts file for unexpected IP addresses and host names.
Hosts file
My thought is that some crapware was loaded onto the build either directly or embedded with some other garbage app. Indeed, perhaps some junk AI as suggested by
@punkncat.
And take another look at the connectivity involved: PC --- Ethernet -----> Router --- cable into the wall ----> ??
What comes next: some other box, a patch panel, a wire leading to some unknown location.....
What make and model router?
Try running "tracert 8.8.8.8" without quotes via the Command Prompt.
What that command does is ping Google's servers and presents a list of the devices/servers between the PC and Google. The first two or three hops being of most interest.