Moving a story from a project you own to a project you do not own loses story
If you are project owner and you try to move a story from that project to another project that you do not own the story gets lost. Just guessing but it seems to me that either it should be allowed and work or it should warn you that you do not own the project your trying to move the story to.
I guess another option that might work is only administrators can move stories between projects.
Statement from Kunagi Team
If the Product Owner moves a Story to a project in which he is not the product owner, an Issue is created. This is consistent with existing concepts in that only the Product Owner of the target project may write the Product Backlog. Issues can be directly converted to Stories.
Issue is closed.