Hello Tom. Welcome to the
Kitz forum.
Having taken a quick look at the information your have provided, along with viewing MDWS, it does seem as if you have a circuit that is at the "far limit" for a G.993.2 (VDSL2) based Internet service. I think we need to let the circuit "do its own thing" and then review the situation after 24 hours have elapsed.
Being a new provision, the circuit is running on fast-path with a "wide open" profile. I suspect that once the first 24 hours have elapsed the DLM will then attempt to optimise the circuit's performance.
I may be wrong but I thought that Ofcom had issued a diktat that all ISPs/CPs must provide a personalised estimate as to the performance one could expect when signing up for their service. So if I'm not imagining it what estimate did your ISP/CP provide, please?