Bill pay is not functional due to violation of CORS

Attempt to pay Comcast bill in a browser that strictly enforces CORS 

The default bill pay url:  https://payments.xfinity.com/new

After about 10 seconds, the user will receive a generic error message "Sorry, this isn’t working right now.  Please return to My Account Overview while we resolve the issue."

Many resources fail to load due to CORS enforcement.
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Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://dl.cws.xfinity.com/event/. (Reason: CORS request did not succeed). Status code: (null).
Loading failed for the <script> with source “https://cdn.quantummetric.com/qscripts/quantum-comcast.js”.

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://metrics.xfinity.com/ee/v1/interact?configId=[Redacted ID]
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://metrics.xfinity.com/ee/v1/identity/acquire?configId=[Redacted ID]

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://yhm.comcast.net/YhmProxy/extension/YHM/?response=json. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 200.
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://yhm.comcast.net/YhmProxy/extension/YHM/?response=json. (Reason: CORS request did not succeed). Status code: (null).