Cannot display branches in gitlab website

I’ve pushed local repository to gitlab (main and current branches) but when I try to display branches, an error message always appears:

Unable to load branches

The git server, Gitaly, is not available at this time. Please contact your administrator.

And if I try to select a different branch from gitlab’s repository page, I get the following error message (red marked):

An error occurred while fetching branches. Retry the search.

Steps to reproduce

Get to the repository page. On the left, select Code->Branches

Versions

Please add an x whether options apply, and add the version information.

  • Self-managed
  • GitLab.com SaaS
  • Dedicated

I don’t know why this happens and how to make branches displaying in the gitlab website.

Any ideas?

Waiting for a reply,

Thanks.