Forked project is not recognized as fork anymore

Hi All,

I’ve had this project https://gitlab.com/arcctgx/slackbuilds forked from upstream SlackBuilds.org / slackbuilds · GitLab for a few years now, and I’ve been using it to contribute to upstream from time to time.

Yesterday I noticed something is broken. My fork still exists, but it doesn’t behave like a fork anymore:

Looks like my project has somehow lost its fork status.

How could that happen? I don’t recall doing anything to “un-fork” my project (if that’s even possible). Is there any way this can be fixed, or should I just create a new fork?