Subgit deletes tags created in git

We use Subgit for syncing some projects in an SVN repository. Now we are syncing a new project and everything looks good. But if we create a new tag in Git, the tag gets deleted by Subgit. That’s not the case for the other projects.

We even tried to disable subgit to see, if anything else is the problem. But in this case the tag is kept. But as soon as we run subgit fetch, the tag is deleted:

Fetching revisions from SVN repository:
Updating refs:
- [deleted]         Test
Sync completed successfully

Other changes are synced and it also works for other repositories.

Do you have any idea, what the problem could be?