Custom Address Field in Base Modules

Is there a trick to adding a custom Address field to base modules (Specifically, projects)?

I’ve added the field(s), and have been able to display them in the ‘address’ type group, but they will not save input data.

I’ve gone back and removed everything I’ve tried to add to get this working, so I’m starting over with a clean slate.

Has anyone successfully added a custom Address field group to a module, and if so, how did you go about it?

There’s no special trick to add Address type field, maybe you have some owner and permissions issue, and also make a quick repair after the custom stuff.

Best Regards