Disabling feature flag has no effect

Hi there,

we’re currently on GitLab-CE 14.09.2 and our Repos typically end with trailing underscores, e.g. “Project___”.
We’ve noticed that such a name is now forbidden.

When trying to create a new repo, GitLab gives the Message: “The form contains the following error: Path must not start or end with a special character and must not contain consecutive special characters.”
I found the following merge request, which introduces this as a feature.
The merge request also indicates that it should be possible to disable it with the feature flag restrict_special_characters_in_project_path.

I’ve tried to do that by typing Feature.disable(:restrict_special_characters_in_project_path) into the ruby console.
The behavior, however, is still the same.
Running sudo gitlab-ctl reconfigure also didn’t help.

Is there something else I need to do to deactivate this feature?
Any help would be greatly appreciated.