Upgraded to CODA56 modem - speed still slow

I recently upgrade my customer-owned cable modem from a NETGEAR CM500 to a Hitron CODA56 after being told my old NETGEAR modem did not support the faster speeds of my plan.  I currently have a 400 Mbps download speed / 35 Mbps upload speed plan.  After installing and activating my new modem using the Xfinity app, I'm only getting ~93 Mbps on any device on my network regardless of it being an ethernet or wifi connection.

Things I have tried so far (using other posts from this forum, and this (https://forums.xfinity.com/conversations/internet/answered-tips-for-troubleshooting-your-xfinity-internet-connection/602da481c5375f08cd7fbb7c)

• Waited more than 24 hours for Xfinity to provision the modem with the new speed (it's actually been over a week now).
• Power cycled the modem (many times).
• Sent a reset command to the modem through the Xfinity app.
• Connected a computer directly to the modem using a Cat6 patch cable.
• Verified that the signal speed between the modem and the computer is fast enough (it was 2.5 Gbps per the modem manual)
• Verified lights on the front of the modem are solid
• Verified that my network adapter is capable of fast enough speeds (It's on auto negotiation, but I've also briefly tried full duplex).
• I attempted to look at the signal levels of my modem.  I am unable to access the CODA56 GUI despite following the steps listed here (https://ussupport.hitrontech.com/portal/en/kb/articles/how-do-i-access-the-gui-on-the-coda56) and setting the static IP.  I was able to ping the modem just fine after changing to the static IP address, so I believe the issue is, per the top of that page, the firmware level which can only be updated by Xfinity.
• Verified that the splitter installed where the cable enters the house is a 5-1000MHz splitter, and is not corroded (splitter is a PCT-NGNII-3S GENESYS II 3-Way Splitter).

At this point I suspect the issue is either a provisioning issue from Xfinity, where I'm still getting the speeds assigned to my old modem, or a signal issue that I cannot check myself.  Can someone help me check on these two possible reasons?

Thank you.