Public repositories not displayed under "Explore"

Hello,
in my Gitea instance, the public repositories are no longer displayed under “Explore” for visitors. When I entered an URL directly I get a 404.
However, when I log in with my account, they are shown normally.

I’m not aware of having changed anything in the configuration.
Gitea is running in an own LXC as a SNAP service and is regularly updated automatically.

Does anyone have any ideas?

Many Thanks!