Try a Hub reset as below and then speedtest as below
Do a Hub “pinhole reset” - first make sure the 2 passwords on the Hub sticker are still there and legible first ! Disconnect any ethernet cables from the Hub (leave the coax connected), and then with the Hub still "switched on" throughout, press pin in firmly with paper clip/SIM tray tool or similar "thin thing" and hold it firmly for at least 60 (a timed sixty) seconds, release the pin, leave for 5’ to stabilise - dont manually switch it off at any time. Passwords will reset to those on the sticker. See if that sorts it.
As 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.
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.