Mirror a github project to local Gitea doesn't work


I am a new User. I use GITEA 1.8.2
I tried to set up a mirror of a github project with a update interval of 8 hours.
In the overview of gitea i see same sync infos, but the local repo is olden then 3 weeks.
On github I see commits every day. A manual sync repo also does not work.

Any idea how to find my mistake?

Many thanks.