I have two cloud functions doing some simple book keeping work.

handleUserIn keeps a trace of a user logging in and handleUserOut keeps a trace of a user logging out.

Below is the code for the two functions:

exports.handleUserIn = onRequest(
  {cors: ["*"]},
  (request, response) => {
    const usrIDParam = JSON.stringify(request.params);
    const userId = JSON.parse(usrIDParam)[0];
    handleUserTrace(userId, "Log-In");
    response.send(0);
  }); /* End of handleUserIn */


export const handleUserOut = onRequest({cors: ["*"]}, (request, response) => {
  response.set("Access-Control-Allow-Origin", "*");
  response.set("Access-Control-Allow-Methods", "GET, POST");
  const usrIDParam = JSON.stringify(request.params);
  const userId = JSON.parse(usrIDParam)[0];
  // corsHandler(request, response, async () => {
  handleUserTrace(userId, "Log-Out");
  response.send(0);
  // }); // End corsHandler.
}); /* End of handleUserOut */

Now comes my question. Though the two functions both do their jobs as expected, when I test them; I get some annoying messages in the developer console of my web browser.

Like the one below:

GET
https://handleuserout-vzu8tf4c5q-uc.a.run.app/xyxCIPDXZXgiR6DsjWx3yFOuXYZ4
[HTTP/2 500  365ms]

GET
    https://handleuserout-vzu8tf4c5q-uc.a.run.app/xyxCIPDXZXgiR6DsjWx3yFOuXYZ4
Status
500
VersionHTTP/2
Transferred370 B (21 B size)
Referrer Policystrict-origin-when-cross-origin
Request PriorityHighest
DNS ResolutionSystem

I suspect I did something wrong concerning the CORS, but I am not confident about that.

Does any one have an idea of where the issue is, and how I can fix it ?