I too been having this problem....I have the gig1 and the brand new hub 5, my series X speed test ALWAYS hits around 1030-1120mbps....AND my pc consistently speed tests at 1130mbps....always....my phone even speed tests at over 800, and that's on WiFi!!!! The console and pc are over Ethernet....but yet my series X is stilo only hitting between 300-400 odd Mbps...it even dips down to 200-100 odd at times... albeit for a couple seconds....but come on...I'm not paying £62 a month for over a gigabit if my console isn't even getting HALF that....it's ridiculous...even my pc, whcih originally started out as consistently downloading at 1.1gbps on steam, has now reduced itself to 700-800mbps....it's ridiculous....