I paid a lot of money to Virgin Media to upgrade from the Hub 3 to the Hub 4 with gig1, but the wifi has been much much worse than with the previous Hub 3. The Wifi connection to my laptop keeps dropping and I'm experience buffering and lagging issues on streaming. I'm extremely unhappy - I upgraded and spent more money to get a better service not worse!
Can you post your Hub status and logs? Someone should be spot if there is a problem Navigate to http://192.168.0.1 (or http://192.168.100.1 - if in modem mode) Don't log in! Click on 'router status' Copy/paste the data from each of the tabs. The forum software will remove the MAC addresses for you (you may need to click the 'post' button again).
Also, set up a 'Broadband Quality Monitor'. This will monitor the state of your connection and record any network dropouts etc - You can do this at ThinkBroadband (https://www.thinkbroadband.com/broadband/monitoring/quality) Give it a while to gather data and then click 'Share Live graph' and paste the 'Direct Link' into the forum!