Google OAuth - Failed to retrieve access token from oauth provider

Hello, I’m using Google Auth only and although the users can log-in normally, Grafana is not forwarding the OAuth token to the data sources (set up to forward OAuth and credentials).

Further investigating Grafana logs, I could see that there are multiple occurrences of the error below (note they are sequentially happening):

t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:30+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:36+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:36+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:36+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:36+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:40:36+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:41:01+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:41:01+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:41:01+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:41:01+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google
t=2020-08-19T03:41:01+0000 lvl=eror msg="Failed to retrieve access token from oauth provider" logger=data-proxy-log provider=oauth_google

I couldn’t find any issue related to this problem before. Any thoughts?

Here goes the settings (ommiting sensitive info):

Grafana 6.4.4

auth.google
allow_sign_up true
allowed_domains foobar.com
api_url https://www.googleapis.com/oauth2/v1/userinfo
auth_url https://accounts.google.com/o/oauth2/auth
client_id the-correct-google-client-id-taken-from-google-console-oauth-credentials.apps.googleusercontent.com
client_secret ************
email_attribute_name
email_attribute_path
enabled true
hosted_domain
name google
scopes https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email
send_client_credentials_via_post
tls_client_ca
tls_client_cert
tls_client_key
tls_skip_verify_insecure
token_url https://accounts.google.com/o/oauth2/token