I’m pretty certain it’s Apple’s private relay and a search indicates that it can be toggled on/off for each website at point of use which helps.
The reason for switching to the faster package was for cost rather than speed as it is £6 a month less!!! I just didn’t want to pick up a 24 month commitment if I couldn’t work around the sluggish access to the Plusnet site.
Thanks to all who contributed above.
