The sync speed of the router could be within the range if he is on the VDSL B (impacted) the Speedtest.net is the throughput, he needs to talk to the cp and find out if they can tell them if they are on the A or B, I am on The B range and lose 30M over 450 - 500 Mtrs due to aluminium cable being in the route. If they get an engineer out it would probably be a super fast visit assure job where the cp thinks it is within range and an engineer will come along with their tester and if they get the sync speed on their tester above what is in their job notes then they won't do anything.
Well I've started a case through BT support so hopefully that will run its course and they'll either magically fix it or I can arrange for an engineer to come out and check it out.
Well I've got an engineer to come take a look at the house on the 23rd. Just hoping they don't randomly find something wrong they can pin me with a charge for. Think everything is solid my end, despite the master socket being in a slightly strange place when I bought the house.
An update but nothing really uplifting. The flow goes like this:
Will report back with what I hear.