​​Ever since I purchased my Arris S33 I do not get the speed that I pay for. I currently have the 1200 Mbps Plan and I have yet to surpass 800 Mbps. Today I had a technician come to my house and tested the speed at the tap > 1600 Mbps plus. Then he tested it at the dmarc where it enters my home > 1600 Mbps plus. Marcus then tested my coax before it connects to the modem inside my home > 1600 Mbps plus. When he connected to the 2.5 GB port on the Arris S33 > 800 Mbps at most. Marcus said that something in the backend isn't set correctly for my modem. I called support and the foreign rep said he couldn't check my modem as they can't touch customer owned equipment and gave me the number for Arris Support. I called Arris Support and after logging into my Arris Modem we checked voltage levels on my downstream channels and upstream channels. The downstream bonded channels were within Arris's specifications (-15 to +15). My downstream channel voltage was -3 to -5 which the Arris tech said was fine. When we checked the upstream bonded channels all (5) were below Arris's specifications (45 to 54). My upstream channel voltages ranged from 35.0 to 36.5 which is out of the range for my modem. The Arris tech informed me that Xfinity could fix the voltage issue by increasing it. ​​

Also I would like to post my home network setup:

Arris S33 Modem 2.5 GB Port > 2.5 GB WAN Port on ASUS - ROG GT-AX6000 Router > 2.5 GB LAN Out of ASUS GT-AX6000 Router > 10 GB LAN Port on Netgear MS510TXUP POE Switch with (4) 2.5 GB POE Ports / (4) 10 GB POE Ports and (2) 10 GB SFP Ports > 10 GB LAN Port > Engenius  EWS377AP Access Point with 2.5 GB Port In. I have spent close to $1500 on my home network devices. With the Equipment that I have I should be able to pass 2.5 GB speeds if I had a 2.5 GB Internet Connection. And as of now the problem is the Arris S33 not giving my network (Router and Switch) the 1200 Mbps speed that I'm paying for.

​​So does my Arris S33 Modem not being set up properly on the back end have anything to do with my speed issue? Can the voltages on the Upstream Bonded Channels be increased by Xfinity? Does my modem need to be re-provisioned?  I would just like to get the speed I pay for. Thanks!​​