For example, if the following was still enabled (it is by default) then all bets are off for WiFi getting all possible access to the air.

Read https://www.howtogeek.com/224981/how-to-stop-windows-10-from-uploading-updates-to-other-pcs-over-the-internet/

Another issue is that WiFi gets clogged up fast if other users are watch Netflix, Youtube and such.

-> What is this about a new machine having WiFi issues? HP is not known for making bug free machines.

Finally 8 devices is a stretch. I doubt anyone has this setup or will tell us it's OK.