So, this finally got fixed this morning!
The delay is mostly my own fault as I couldn't get time off work. Long story short:
OR booking 1: No show but I showed a resynch that morning.
OR booking 2: A very helpful chap turned up (thanks Mark) and found that I had always had a bridge tap within my extension wiring (I rent). He fixed that and put a shiny new faceplate thing on the wall (Master Socket 5C). My ping was still double what it should be but I noticed my attenuation was now 3dB less than before. Seeing there was a visible improvement to the line, I let him go and crossed my fingers that the cab would notice things were looking tip top.
That was Thursday morning.
It's now Saturday.
I game every day and habitually check base latency before I start - so I have nothing to blame but myself for my poor performance
I checked just now and I'm finally back to 10ms UK RTT.
Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=10ms TTL=124
Reply from 8.8.8.8: bytes=32 time=10ms TTL=124
Reply from 8.8.8.8: bytes=32 time=10ms TTL=124
Reply from 8.8.8.8: bytes=32 time=10ms TTL=124
Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 10ms, Maximum = 10ms, Average = 10ms
I still have the SR102 attached atm but I am now also showing full sync, as it always should have:
Broadband Link Downstream Upstream
Connection Speed 79999 kbps 20000 kbps
Line Attenuation 9.7 dB 0.0 dB
Noise Margin 6.6 dB 14.14 dB
Speedtest looks good too, attached.
Funny thing is, I saw an article posted the other day that Sky had somehow tied bottom place in some ISP ranking.
I didn't believe it for a second.