GitLab will be upgraded to version 18.3 on September 17th between 20:00 - 23:00, services may be unstable and/or unavailable during the given timeframe.
As this is a major upgrade, please review the release notes incase anything in your project/group is affected: https://gitlab-com.gitlab.io/cs-tools/gitlab-cs-tools/what-is-new-since/?tab=deprecations&minRemovalVersion=17.11&maxRemovalVersion=18.03