I'm in East Kent and it is showing as the worst area by TBB metrics. Dover and Folkestone are 7 miles apart and are both in the worst 10.
I have noticed these issues and I get dire speeds in the evenings. Every summer during the school holidays the whole thing goes to pot too. There doesn't seem to have been any network investments in this corner for a long time now, but there has been infill work in some parts of town adding to the load. The CMTS I'm connected to is a BSR 64000 with 12DS and 2US still on 16QAM. I wonder if we will get any improvements anytime soon.
here is my 200/12 speed at 11:18am today