Hi again
I did as you said and connected to the test socket, the info was different this time around (and the cable inside the socket was a bit of a mess - green-white just dangling about although not sure if it is used for anything)
Weird thing was that the BT wholesale test was returning 0Mbps upload speed. Download was still almost exactly 40, but this time on a non-bt speedtest upload was much higher - around 19Mbps to the 11 previously. So I have no idea what is going on with that.
Router was reporting higher max download on the Helpdesk data, but nothing was actually getting that speed anyways.
So, at least we know now that the technician did very little and that there is likely something technical going on. Here's data I was getting on the test socket:
Here's what was on the main socket after I've put it back together:
and that's the result of the wholesale speedtest advanced phone line check:
It seems BT is doing some changes today so that may be a reason of a weird line test, app claims I don't have an account...