FS can't be moved to part of town (Stadtteil) anymore

Summary

When trying to push an FS to another main region, it is not anymore possible to select a region of type 9 (part of town)

Steps to reproduce

1. create a new region of type 9 (part of town)
2. Be AMB of a region.
3. go to edit profile of an FS in your region.
4. Click on "Bezirk ändern".
5. Try to select the newly created part of town.

What is the current bug behavior?

"Sorry, Du kannst nicht als Region ein Land oder ein Bundesland auswählen."

What is the expected correct behavior?

Shoud be possible to select and to move an FS to such a region.

Relevant error messages and/or screenshots