Arris rejecting CM Config for invalid TLV-4

A new DOCSIS 3.1 Arris G36 is unable to activate after it receives, but finds invalid content in xFinity's CM Config file.  The logged error identifies TLV-4, but not a specific sub-value.

TLV-4 contains 'Class of Service', which appears (in DOCSIS 3.1 materials I have found) to be:

         ClassID;                             /* TLV: [4.1]*/
         MaxDownstreamRate;      /* TLV: [4.2]*/
         MaxUpstreamRate;        /* TLV: [4.3]*/
         UpstreamChannelPriority;/* TLV: [4.4]*/
         MinUpstreamRate;        /* TLV: [4.5]*/
         MaxUpstreamBurst;       /* TLV: [4.6]*/
         CoSPrivacyEnable;       /* TLV: [4.7]*/

Is there a fairly recent (late 2024, early 2025) DOCSIS change to the CM config file implemented by xFinity but not [yet] part of Arris' firmware?

Is it possible there are different config files for xFinity-provided gateways than for off-the-shelf Arris G36, and why wouldn't first-level-support know about this?

Anyone offer any suggestions? I have no internet until a path forward is identified for this xFinity-supported device.  It appears the only two solutions are xFinity 'fix' the config file it sends to me or xFinity pushes a Arris firmware update to my device.

Thanks!