@ajo I'm glad to see that the issue is now resolved. Thanks for posting your solution so that others experiencing the same thing can easily reference this. Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer, they can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.
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Issue: You are not able to see the diagnostic logs from Azure Document Intelligence.
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Resolution: The log ingesting takes sometime. Post waiting for sometime and querying again, you were able to see the logs.