Connect tasks over multiple group hierarchy levels not working

Hello together,
we struggling around with the task feature for issues.

We have 2 groups on the same hierarchy level (product and development), plan is to have a userstories project inside the product group and then cutting down these issues into smaller task inside the development projects.

Example:
product/userstories
development/frontend/X
development/backend/Y
development/…/Z

The problem now is, gitlab doesnt find the projects inside the development group. Its possible to create tasks under an existing issue inside of one of the development projects and link it to an issue inside the projects/userstories project. But that very unhandy, did anyone else has the same issue or some idea whats going wrong?

Best regrads