Hi
Virgin's "preferred" speed test is "speedtest.net".
This will show what you are actually getting ....
(do not take the first test result but keep a tot of what you get)
... not what you are contracted for.
The ex-BT engineers (et al) on the site are correct, however your modem/router is likely (off) the first point on the connection in and therefore not likely to be (so) affected by REN.
If your "broadband" (as you call it) is a wireless signal "inside" your home then the problem may well be caused by the building make-up of your "home". Simple things like you have placed the w/l router near/next to a freezer / metal filing cabinet / metal shelving / "upandover" garage doors/ the castle walls ...............

or your coronet or throne!
