Not able to add backend service

Hi All

I have the following problem. I've created an odata service with tcode SEGW on the backend system. If I go on this system to transaction /IWFND/MAINT_SERVICE I can add the service with local.

Now I want to add this service to a frontend system but there if I run /IWFND/MAINT_SERVICE and add the alias of the backend system I can't see my newly created odata service. I receive some backend services so the connection itself shouldn't be the issue.

Do I miss something in the odata definition or what could be the issue?

Thanks a lot for your help.