Hello debanjan c,
Thank you for reaching out to Microsoft Support!
For your problem, the above two users seem to have the same experience, for this occasional problem, may be due to API upgrade or update caused, you need to wait for a period of time to retry, the problem will be automatically resolved.
Similar questions:
https://learn.microsoft.com/en-us/answers/questions/759462/graph-api-list-places-give-401-error
Hope this helps.
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