Error 4033 GitLab self Hosted

I am trying to get my GitLab CE hooked up to Plane with Pro subscription.

I am using the latest docker compose installation method for Plane.

I am using the GitLab Enterprise integration as when using the normal GitLab integration I just get redirected to gitlab.com with no way to define a self hosted one. I can't see a GitLab Self-Managed integration like the documentation says.

I have configured GitLab application, I can authorise the App, but when getting redirected back to Plane I get redirected to:-

https://<plane_url>/error/?error=4033

With the following screen shown.

I have checked the docker-compose file and also the logs, but I have been unable to see any settings or entries in the logs that could help point me in the right direction.

Does anyone have any ideas where I need to look or what I need to do to get it working?

Thanks

Start by reviewing the Docker Compose configuration and the GitLab application settings used for the integration, then inspect the available logs around the redirect to error 4033. Done means a self-hosted GitLab CE instance can authorize successfully and redirect back to Plane without the error.