Dropdown for user selection to reassign placeholder not loading

The dropdown for selecting the github user to reassign from a placeholder user is always loading. So it is not possible to select a gitlab user there.

gitlab-org/gitlab#555947 (comment 2634354382)

Self-managed gitlab community edition v.18.1.2 on a Debian 12 VM.

It works on gitlab EE v.18.1.2.

Thank you very much