Form Recognizer custom model analysis - GET Analyze Form Result always returns "notStarted" status

Question

For months we have had no issues with Form Recognizer, and suddenly all our requests for custom form analysis are getting stuck in "notStarted" status when we check on it using this api call: https://centralus.dev.cognitive.microsoft.com/docs/services/form-recognizer-api-v2-1/operations/GetAnalyzeFormResult/console. (Form Recognizer v2.1)

This particular request has been stuck not started for over 12 hours:

{
  "status": "notStarted",
  "createdDateTime": "2023-10-24T23:41:57Z",
  "lastUpdatedDateTime": "2023-10-24T23:41:58Z"
}

Additionally, we cannot analyze custom models in form recognizer studio. We get this popup after it spins for a time:

This error doesn't make much sense because we are using the same endpoint and credentials in form recognizer studio as the request that is returning not started, and we have verified they are not different than what is in our Azure portal.

I have seen a few other questions similar to this get posted and saw no resolution. We had this issue back in December of 2022 and through a support request Microsoft was able to resolve it, but I have had a severity A support request open for over 12 hours with no response on our paid Standard support plan.