There's these little wifi extenders that you can plug into an outlet on the main floor. They're a dime a dozen in the big cloud stores. Find a first floor location spatially about half way between the 2nd floor wifi router and the basement spot you'd prefer to work, and plug it in and get it connected to the main wifi.
Whatever you find, try and match it to the main router's wifi standards and bands. Or get even higher-rated repeater for longer term compatibility with upgraded main routers.
Assign a static IP address the nic at each PoS computer with a bogus gateway ip address and no DNS server entry.
That computer won't find the internet but still will communicate on the local lan.
Then add hostname/address pairs in its HOSTS file as needed.
Starlink. Or its LEO ISP competitors like Amazon, within a few years.
If you can install a program or service on your restricted work laptop then try Twingate.
Line of sight wireless bridge. They have high gain directional antennae and run on POE. Look up Adalov wireless bridges. My 2km (smallest range unit) bridge works flawlessly through some trees over about 300ft.
Which browser? What phone OS?
Asking because some browsers now come with an option to use their built-in free vpn.
If your's is such a browser, then the vpn option may have been turned on somehow?
Also, have you tried using private browsing mode on another browser, like firefox?
Put a cheap 4-port gigabit ethernet switch at the observatory end of the existing cable then if the switch in the house is LAN-connected that new observatory switch will provide wired internet access too. Then plug a patch cable from the new switch to your equipment's original ethernet connection port to run it, too.
Plug a wifi AP into the observatory switch for added wireless access there, too.
This is what I use.
Note that widening the channel may or may NOT increase 5Ghz wifi throughput.
A couple of reasons that I know of:
- at that "center" channel 62 any widening would overlap the very busy looking 44 next door, i.e. increase in interference..
- many client device's can't use 40 or 80Ghz-width 5Ghz channels anyway.
I have a pfsense CE firewall, free, on an old mini desktop. The web-configurator has a traffic graph status page that lists every connected device's bandwidth in and out, updated every second. An overall LAN/WAN traffic graph too, of course.