Back to first principles. If you think that you have a BB speed problem, then to check the speeds coming in to your Hub properly, and whether they match what you should be getting, you cannot rely on wifi tests, - no BB supplier guarantees those - only speeds "to" the Hub are guaranteed. So, you need to do it directly.... that's on an ethernet cable connected computer/laptop with the Hub in modem mode.
So if you are expecting >100mbps, make sure that your device has a gigabit network card (not a 10/100 one or one that is “limited" to that in its settings or you will never get over ~100mbps) and has the most up to date drivers. Use a new Cat6a ethernet cable (old ones do "fail" and Cat6 is best) to connect it directly to the Hub - which you have put into modem mode (see VM website for the "how to") this ensures only your one device is connected. Check speeds like that first.
If they are still low - then, boot up your (Windows) device into "safe mode with networking" (to disable any software on it that could be limiting speeds - lots do!). Run your speedtests at speedtest.net (do them on x2 close VM servers) using 2 different browsers - preferably with one of which is a fresh download of one you haven’t previously used (e.g. Firefox, Opera, Safari etc) - there are several reports on here of certain browsers causing speed issues.
Try that and report back what you get.
--------------------
John
--------------------
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.