Update .
not long got back.
Landlord away so Did not touch anything of the 'Mess' of the set up.
What I did do, Speed test on my phone app in the tenants flat = 0.34 Mbps Down and 16.5Mbps up
before I started.
Then plugged into a wall mains socket a spare TPLink AV600 power line Extender, plugged in the Ethernet patch cable from the wall socket into one Ethernet port on the bottom of the above device, plugged in another patch lead into the second port and then into the laptop.
Powered it up, checked on my phone app and the download had gone up to 22.7Mbps and up 17.9Mbps
also good speed check results down stairs.
I told the tenant that on there phone only to have this new SSID network for the WiFi.
I will give my recommendations as what the landlord could do to improve the set up to the tenant, the other five tenants are all moaning about the Poor WiFi in some parts of the property.
Looking under the stairs where the VM box and router is located is far worse than I suspected with metal step ladder type steps, a vacuum cleaner (metal) and a lot of junk in there ,not sure how any WiFi signal gets out.