Docker Login to Gitlab Registry fails

Hello, i have a pipeline with some docker images from a private gitlab registry.

Yesterday everything worked fine, but today all my pipelines fail on docker login..

pipelines:
 default:
   - step:
     name: Install dependencies
     services:
       - docker
     script:
       - docker login -u ${DOCKER_GITLAB_USER} -p ${DOCKER_GITLAB_PASSWORD} registry.gitlab.com
       - docker pull registry.gitlab.com/<somerepo>/<someImage>:latest

Login works from my machine, from a server etc. Only the Pipeline seems to have problems.

Does anyone have a solution?

best regards