Thank you for posting this in Microsoft Q&A.
I understand you are trying to exclude the CMG Server Application from Conditional Access Policies, but it was not present under the excluded conditional access policies.
Can you please confirm have you created the Server Application in Microsoft Entra ID, as mentioned in this document
I have created the Server Application in Microsoft Entra ID and was able to exclude that application in the conditional access policy.
Hope this helps. Do let us know if you any further queries.
Thanks,
Navya.
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