Signin with Gitlab stopped working

Oauth with gitlab is failing

We were using Sign in with Gitlab in our application and suddenly last to last thursday, 22 april, it stopped working and our calls for getting the access token started failing. Has something changed in the gitlab’s side for supporting oauth or has any header / field has become mandatory?

Also, does the Application secret has any expiry time? Could this be one of the reason? I tried by creating a new key as well but still no luck.