Error connecting with Gitlab via JWT

i haven’t used Vault before and now have to take care of a previously set up Vault-Server with Gitlab CI/CD by using JWT (CI_JOB_JWT generated by Gitlab) for enabling access of the vault by the gitlab runner.

While curling the /v1/auth/jwt/login - Endpoint I get the following Error

error checking jwks URL: error=“fetching keys oidc: get keys failed Get "[jwks_url]”: dial tcp: lookup [bound_issuer] on read udp> i/o timeout"

I have masked the jwks_url and bound_issuer, the urls are correct.

The Vault-Server is deployed in a Docker Container. After a problem with the Docker Daemon the Vault-Container was down and restarted. The configuration and secrets don’t seem affected by the restart as they are saved in a volume. Because the JSON Web token is provided by the gitlab-instance and masked in den logs I cannot verify otherwise the token.

Maybe someone can say, if this is an internal problem of Vault oder a network issue.