Ok - can you test speeds like this first
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, can you test speeds directly like this. If you expect >100Mbps then connect a 1GB enabled computer/laptop, with up to date drivers, via a NEW and working Cat5e/6a ethernet cable, directly to the Hub which you have put into “modem mode” (https://www.virginmedia.com/help/virgin-media-hub-modem-mode ). This ensures that NO other devices are connected
Test speeds at https://speedtest.samknows.com/ - try on 2 different browsers.
If they are still low – boot your device into Windows safe+networking mode - to disable any potentially interfering software - and try again.
There are many posts on here (I have a list of ~30!) where QoS software, unknown/flaky software, old network card drivers, corrupted browsers, bad cables or other connected devices are limiting speeds on tests.
Report back what that gets. There was one thread on here earlier this week where a 1GB customer was getting terrible speeds - they booted into S+N mode and speeds went straight to 980Mbps. Something on the PC was limiting them
See message 6 here...
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired, 1 WiFi, 1 on PA) Hub5 in modem mode with Apple Airport Extreme Router +2 Airport Express's. On 250Mbps, Talk Anytime Phone, x2 Mobile SIM only iPhones.