CORS-issue in cloud function

For a few days now I get a cors-error when executing my cloud function:

Access to fetch at 'https://us-central1-hauzr01.cloudfunctions.net/getObjectInfos2' from origin 'https://ff-debug-service-frontend-ygxkweukma-uc.a.run.app' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

Also the deploy region doesn't seem to fit. I chose "europe-west3" but the cloud logs say it is deployed in "us-central1".

I tried copying the function, but it didn't change anything. If anybody is interested, it is a function to use the OpenAI-API:

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const OpenAI = require('openai');

exports.getObjectInfos2 = functions.https.onCall(async (data, context) => {

    const openai = new OpenAI({
        apiKey: 'sk-...',
    });

  const strInput = data.strInput;
  const strSystem = data.strSystemMsg;

  try {

    completion = await openai.chat.completions.create({
      messages: [{
        role: "system",
        content: strSystem
      },
      { 
        role: "user", 
        content: strInput
      }],
      model: "gpt-4",
      temperature: 1,
      max_tokens: 2000,
      top_p: 1,
      frequency_penalty: 0,
      presence_penalty: 0,
    });

    console.log(completion.choices.length);
    console.log(completion.choices);

    if (completion.choices.length>0) {
      const generatedText = completion.choices[0].message.content.trim();
      return generatedText;
    }

  } catch (error) {
    console.error('OpenAI API request failed:', error);
  }
  });

I contacted FF-support today, let's see what they say.

Does anybody experience the same problem?