It happens! I had exactly that issue and it took several Technician visits to resolve it - three or four averaging 4 hours with second and third line support on the phone. It just suddenly changed from 9.xx to 16.xx we had been seeing the slow upstream and then suddenly it changed. No one could explain it - but possibly a database update resolved it.
The BT Techs used a secure login to a BT system and that was showing 18Mbps and it was testing as such, went back to mine and just 8 or 9 ... so the line was capable. Tried both Huawei and ECI modems, older 2wire 2700/2701 and BusHub3 routers, the support side kept reloading profiles and updating.
A little more work with the modems and we then pulled it up to 56/18
xxx/9.52 at 12:56
xxx/9.53 at 13:22
xxx/16.91 at 17:34
and then up to 18.46
M H C
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