OAuth Auto Login Bug with Sub Path – Double /grafana/grafana in URL (v11.x, No Proxy)

Grafana Configuration
1

Hi Grafana Community,

I’m experiencing an OAuth auto login bug when using a sub path in Grafana.
This issue causes URLs like /grafana/grafana/... (double /grafana/) to appear instead of the expected /grafana/....

Environment

  • Grafana Version: 11.5.7 (also occurred in 11.6.3)

  • Deployment: No reverse proxy (direct access)

  • root_url: https://aaa.domain.com/grafana/

  • serve_from_sub_path: true

  • oauth_auto_login: true

Issue

When auto-login via OAuth is enabled,
the Referer and some internal redirects/links are generated as /grafana/grafana/...
instead of /grafana/....

For example:

Referer: https://aaa.domain.com/grafana/grafana/d/xxxx/...

This causes dashboard access and plugin API requests to break.

What I Tried

  • Disabling/enabling oauth_auto_login – bug only appears when enabled.

  • Checking root_url and serve_from_sub_path values.

  • No reverse proxy (accessing Grafana directly).

  • Removing plugins (such as grafana-lokiexplore-app) – issue persists.

  • Restarting Grafana after config changes.

Expected Behavior

  • All URLs should be generated as /grafana/...,
    not /grafana/grafana/....

Question

  • Is this a known bug in recent versions?

  • Are there any workarounds or settings to avoid this double sub path issue?

  • Any recommended configuration for OAuth auto login with sub path?

Any help or suggestions would be greatly appreciated!

Thank you.