For years the geodns server has had a misconfiguration so users in Great Britain by default (accessing the non-country-code domain) would get a European server rather than a more local one.
The zone in the NTP Pool system has always been called ‘uk’, but the GeoIP library returns ‘gb’ for the relevant users. Oops! The system didn’t have a ‘gb’ zone configured, but knew it was in Europe so would fall back to that.
I fixed it about 3 weeks ago, so since then users in that region should be getting better service.
Related then servers registered in the ‘uk’ zone will have seen their traffic go up considerably. If you need to adjust how much traffic your server gets, you can adjust the netspeed on the manage site.