OmniAuth/Sign-In with Google not available on sign-in page, but working for existing users and auto_sign_in_with_provider

Hi.

I am trying to use OmniAuth with the google_oauth2 provider.

Having enabled omniauth and configured app_id/app_secret in gitlab.rb/gitlab.yml, I am able to connect existing users to google-accounts in User Settings/Account/Social sign-in (after clicking “Connect” and signing in with google, “Authentication method updated” shows on top of the page).

However, on the sign-in page of GitLab, no option/icon is presented to login with google, only normal username/password login is available. I understand that I should see the same “Sign in with Google” icon as on https://gitlab.com/users/sign_in.

Sign in with Google does work if I set auto_sign_in_with_provider. However, I would like to still offer sign in with user/password at the same time.

I found the following issue also describing my problem: https://gitlab.com/gitlab-org/gitlab-ce/issues/22871

I’m running gitlab-ce 9.0.2 on Ubuntu 16.04.

Any help would be much appreciated.
Thanks!

Update: When adding GitHub as an additional provider, it does show the github-icon on the sign-in page. I also notice that in Admin Area/Settings/Sign-In Restrictions, both Google and GutHub are displayed, but only GitHub is enabled. I cannot change the status of either there however.