Hi @sumak,
Could you please share a screenshot of your flow's configuration?
Further, could you please show more details about the error message?
Based on the error details that you provided, I think your issue is related to authentication error. Please check if there is a authentication error with the connection to the trigger of Visual Studio Team Services connector within your flow. Please refer to the following article to fix the authentication error:
https://docs.microsoft.com/en-us/flow/fix-flow-failures#authentication-failures
I have made a test on my side and don't have the issue that you mentioned. My flow's configuration as below:
The flow works successfully as below:
Please refer to above article that I provided to fix your authentication error, then try your flow again to check if the issue is solved on your side.
Best regards,
Kris