Big drop in download speeds after upgrading internet service and activating new XB7-T gateway
Previously, I was running the XB6-T gateway with xfinity blast 300 Mbps down/10 Mbps up. Everything had been great with no complaints. When I ran speedtests, the results were always within a satisfactory range. I primarily run speedtests on testmy.net, but I also try speedtest.com and the xfinity branded speedtest from time to time.
Earlier this week, I upgraded to the 900 down/20 up service, which required for me to upgrade to the XB7-T gateway. The new gateway took about 3 days to arrive. During that time, I ran additional speedtests while still using my old XB6-T. I was getting max speeds around 600 down and a solid 23 up every time on the old gateway with the upgraded service.
My new XB7-T gateway arrived today. I have activated and have been running speed tests. I am getting less than 300 down, but still a solid 23 up every time. I have checked on gigabit ethernet connected PC, laptops on 5G wifi, and mobile phones. I have disconnected all of the other devices, and they are still all getting consistently slower results.
Could I have a bad modem? Is there something that can be calibrated to improve the speeds? Why would an XB6-T be able to pull down 600, yet an XB7-T can't do half of that?
Thanks in advance for the assistance.