@Bryan Robbins - Welcome to Microsoft Q&A and thanks for reaching out to us.
There was an intermittent issue on Application Insights API endpoint during May 9th timeframe.
The workaround as victor mentioned Users may rely on using Entra ID authentication instead of API Keys to issue the data queries - Application Insights API Access with Microsoft Entra authentication - Azure Monitor | Microsoft Learn"
I am glad to hear that the issue is resolved for you now.
Hope this helps. and please feel free to reach out if you have any further questions.
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