This is really intriguing. From what I can tell, Origin's network is segmented in half; a CGNAT side used for most customer connections, and a static IP side.
My main Origin line has a IP, and almost always hit the same LNS (10.0.254.93), which gets the same HE transit. I have another two CGNAT lines that hit random LNS' and almost always get Cogent transit.
Origin used to have LINX and LONAP public peering, but they culled them sometime last year. It was a wise move IMO. Less traffic to bulk around docklands, so it works out cheaper for them, because transit is cheaper to upgrade than adding more cross/interconnects.
I always observe niggling issues on the CGNAT lines, with stuck TCP connections (probably TCP-SYN issues), particularly to busier local sites like BBC. Before COVID-19, some evening peak congestion was evident. Nowadays, the 40/10 line halves throughput during the evening, and 80/20 about halves throughput too. But it's not a problem for me as they're lightly used and work flawlessly for their intended purpose.
However my main Origin line with static IP hits full 80/20 all day and all night. Never, ever, get any congestion. It's practically uncontended. I don't know whether I'm hitting lucky with the LNS (10.0.254.93) or what. I notice your HE route and you're on a neighbouring LNS (10.0.254.95), so I'd say either your LNS is hot, or its backhaul is congested. It's definitely not a transit issue.
So what I'd suggest is to disconnect your modem entirely for 60 minutes to let your session completely expire throughout Openreach, TalkTalk and Origin's networks, and then reconnect. Maybe you'll connect to a different LNS (take note of the IP, it's the second hop in your trace) and the speed issue will be resolved. If you do get a different LNS but still face evening peak congestion, it'll be TalkTalk's network at fault.
TalkTalk don't often publish info about congestion, but if it's the case here, you might find some planned works on their status page: https://managed.mytalktalkbusiness.co.uk/network-sta...
Edited by olorinh (Wed 22-Apr-20 23:46:03)