Add listing does not use CTP forms – redirects to Homepage

Hello,
I am using different CPT like gd_place, gd_event, gd_travelfriend, … and I use different forms with customed fields for this forms. If you use the “Add Listing” to post a new place, event, …, the form for this add listing appears and you can add your content. This worked until yesterday.

Since yesterday, if I try to “Add Listing” at the FRONTEND, it seems I get redirected to the Homepage. One form still works as usual – if I “Add Listing” travelfriend, the form still appears like usual and all works. I compared all CPT Settings and all are created in the same way.

So I Added another Post Type (gd_test) to try if a new one works. And the new one worked.
Inbetween, I made one change: I activated the GeoDirectory “Social Importer”. It was already installed and worked before. I just reactivated. Meanwhile, I deactivated it again, but nothing changed.
In the BACKEND, all forms appear and work like they should.

Has anybody an idea or a solution?

Sorry for my bad english – I am from Germany. And I am a bloody beginner and working on localhost to create my project.

Thanks for your support!

The images show the CPT with the different post types (gd_reisepartner (travelfriend in english) and gd_test are working.
The add listing image shows the “Add Listing” options.