Firefox Extension CORS error but not happening in Chrome

I get an error on firefox:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://scholar.google.com/scholar?q=%22Techniques%20in%20Testing.%22%20HS%20Madsen%20. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).

The error is raised by the background script and this particular function:

async function webQuery(type, url, data) {
    const params = {};
    params.method = type;
    if (data !== '') {
      params.body = data;
    }
    const response = await fetch(url, params);
    const result = await response.text();
    return { status: response.status, ok: response.ok, result };
  }

Manifest permissions:

"permissions": [
    "identity",
    "cookies",
    "tabs",
    "storage",
    "http://localhost/",
]

What am I missing? It is peculiar that it works on chrome