Unexpected Teams API Error in Lambda: Anyone Experienced This?

Question

I am a web system developer using Python. Yesterday, in our system, an error presumably related to the Teams API arose, and I was unable to determine the cause. Hence, I'm reaching out for guidance here.

[Details] Up until yesterday, the following three Lambdas, which managed the Teams message sending process, had been functioning without issues for a year. It's worth noting that we haven't made any recent alterations to the program related to the Teams procedure.

[Lambda①] No error logs from Teams were produced; only logs indicating that the Lambda process had been successful were generated. (Note: The absence of error logs might hint that we potentially failed to catch the errors correctly.)

[Lambda②] Similarly, no Teams error logs emerged; just the logs confirming successful Lambda execution. (Note: The lack of error logs suggests there might have been a failure in appropriately capturing errors.)

[Lambda③] Teams error logs were detected, which read: "urllib.error.HTTPError: HTTP Error 500: Internal Server Error".

Considering we've used the current code for a year without encountering this error, it's unlikely there's an issue with the logic. Today, the same Lambda, executing the same Teams process, completed successfully. This leads me to believe that there might be an issue with the Teams API. Has anyone else experienced a similar situation?