Axios withCredentials not working on production


I’ve built a backend with Python flask and a web, android app with Ionic. When the backend server is on my local PC Axios withCredentials works fine, saves session tokens into cookies and app works fine.

When I switch the axios baseurl to my production server with SSL after a successful login the session cookies not being saved.
Running requests from Postman on the same server works fine.

There’s no error shown on server and app.

My axios config looks like this.

export const instance = axios.create({
  timeout: 10000,
  withCredentials: true,
  baseURL: "",
  headers: {
    "Content-Type": "application/json",

What could be the issue?