My smart hub currently shows my Downstream Sync Speed at 49Mbps, but actual speed tests, including Openreach's availability checker put my speed at around 35.
So what's happening here, is the router wrong?
post your hub stats and also results of dslchecker
The speed check shows slightly better results today, but there's still a difference. And last night the same test was showing 34.7.
the router shows your connection speed which is near top of expected range. the download speed is always less than connection speed to allow for overheads. if you run btspeedtester diagnostic test you will see your profile which allows for the overheads and your download speed will be less than your profile
https://www.speedtest.btwholesale.com/