XiD-P TV box not working after replacing Xfinity router with Netgear cable modem

Hi there! Apologies for the long post. I've searched these forums for answers, but I can't quite find a scenario that matches mine.

I have an X1 Double-Play internet/TV package. Initially, it was professionally installed by an Xfinity technician. Internet connectivity to Comcast and in-home WiFi was handled by an Xfinity supplied Technicolor CGM4140COM voice and data modem. Cable TV box service is provided by an Xfinity supplied Pace XiD-P (PXD01ANI).

The coxial cabling was installed as follows:

• Wall outlet -> 2-way coaxial splitter:in
  • 2-way splitter out:1 -> Technicolor router coaxial
  • 2-way splitter out:2 -> Pace XiD-P TV box coaxial in

I recently replaced the Xfinity supplied router with a Netgear CM1000 cable modem and Netgear Orbi wireless mesh system. The cable modem is approved by Comcast to support my service (referencing mydeviceinfo.xfinity.com). My internet and wireless services are activated and working normally.

The coaxial cabling is unchanged from the Xfinity technician's installation with the exception of the Netgear cable modem replacing the Technicolor router:

• Wall outlet -> 2-way coaxial splitter:in
  • 2-way splitter out:1 -> Netgear cable modem coaxial
  • 2-way splitter out:2 -> Pace XiD-P TV box coaxial in

However, the Pace XiD-P TV box can no longer connect. The TV is displaying "Sorry, we're having some trouble. Please tighten your cable connection then restart your TV Box, which can often fix common issues." There is also a code "RDK-03036" in the bottom right of the screen. I've tried tightening all of the connections, restarting the TV Box, remotely resetting the device using Xfinity's website, re-establishing the cable modem's connectivity, and contacting Xfinity support for assistance. I'm still getting the same error.

What am I missing? Is the XiD-P capable of working in this configuation? There is no other Xfinity equipment installed in my home and I've read that the XiD-P is a companion device that requires another device with a tuner installed for connectivity to Comcast's cable services.

Any assistance will be greatly appreciated. Thanks.