Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 65618/13914Kbps @ 600m. BQMs - IPv4 & IPv6
It's possibly a duff DSLAM port. The router logs show it eventually making a VDSL connection so your line is definitely connected to a FTTC port
Could that port be in the exchange, or is it always in the cabinet?
I've had the port changed at least once. After one change my disconnections increased by a factor of 3 for almost a week until Openreach were called out again.
Sun 19-Mar-17 10:00:22
FTTC will have fibre to the cabinet, there are one or two with a microwave wireless backhaul but makes no difference to the VDSL2 side.
VDSL2 modems are backwards compatible with ADSL/ADSL2+ so when set to auto mode it would not surprise me to see logs trying VDSL2 first, if that fails to then try ADSL2+ modes, which is what the log is telling me.
Maybe the engineer was attempting to explain that maybe there is an issue with the splitters and some ADSL signal is bleeding through and needs that addressing.
One of them said that he replaced a wire between the exchange and cabinet. He had to wait for someone to allow access to the tunnels. Another said that there was a difference in length between two wires between the exchange and cabinet. She used so much jargon in such a short space of time that I was left with shellshock!