I don’t normally post on the forum but just like to provide my experience on recent upgrade from Internet 600 to Fibre+ Gig plan.
My previous XB6 “Technicolor” was stuck around 600mbps download after upgrade to Gigabit plan for several days; multiple check on modem provisions, RF signal looks good, Cat6 Ethernet, Gigabit Network Card, tested both router/bridged, direct/wifi, the tech gave up and issued replacement of XB6.
The new XB6 arrived today, it’s the “Arris” version, reprovision and running in bridge mode now, download is now at 900mbps.
Maybe bad luck with the Technicolor XB6.