PageSpeed Insights API returning 401 error at seemingly random times

Question

We are programmatically calling the PageSpeed Insights API for an internal list of websites. The majority of the time it works fine, but at seemingly random times we are getting the error "Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential..." When the error occurs we log the url that was used for the request as well as the error. As a result I can copy the exact url that generated the error and paste it into a browser (or Postman), https://www.googleapis.com/pagespeedonline/v5/runPagespeed?url=https://www.xyzsite.com/&strategy=mobile&locale=en&key={validAPIkey} for instance, and get a valid response. The fact that the same API key is being used for all requests I know it's valid so I have no idea what might be causing this error. Has anyone else run into this? Does anyone have any idea what might be causing this error to occur on a seemingly random basis?

Answer 1

I also experience the same issue. As on page 5 to 10 API are called with same API key and credentials. Token is also not expired but it generate 401 randonly on different API. See attached image