@Dennis Tei-Muno Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
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Could you please confirm if you are using the api-version
2023-10-01 in your Azure Computer Vision endpoint ?
If you are using custom model, please use the api-version 2023-04-01-preview
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Hope this helps. If you have any follow-up questions, please let me know. I would be happy to help.