Single click filter dropdown not showing all options

When you one-click on an existing filter, it should show all options.

Currently this is not the case as shown in the gif, for labels and milestones.

Reproduced locally on master, with Safari, for CE.

Previously, https://gitlab.com/gitlab-org/gitlab-ce/issues/31757 was implemented to change from double-click to single-click. But even prior to that change, this bug existed of not showing all options.

cc @ClemMakesApps

changed milestone to %Next 2-3 months in gitlab-foss

changed the description

removed regression in GitLab FOSS label

moved from gitlab-foss#33593 (moved)