At the moment it's possible for Users to add Issues to a Future Sprint from a different board. This causes a single sprint to be started on multiple boards with no indication that it's the same Sprint.

How to Reproduce

1. Create 2 projects A and B both with separate Rapid Boards
2. Create a planned Sprint on board A called Sprint Alpha
3. Create a planned Sprint on board B called Sprint Beta
4. Drag an issue on board A into the sprint
5. Go to the Issue View in JIRA for an issue in Project B
6. Edit the Sprint field, select Sprint Alpha (note that it does NOT warn you it's from a different project)
7. Sprint Alpha will now appear on the Scrum board for Project B
8. Start the Sprint in Board A
9. The Sprint will now also be active in Board B
10. Closing one sprint closes the other as well

There are a few results of this

• You need Project Admin for both boards to be able to start the sprint
• There is no indication on either board the Sprint contains issues from another board. Both boards act like it's their own contained sprint.
• Ending a sprint on one board requires Project Admin for both projects
• It LOOKS like sharing the same name causing sprints to be linked however it's the same sprint in both boards.

Possible Solutions

• Warn the user that the future sprint is from a different board
• Warn the user when starting a new sprint that it contains issues from a different board

Workaround

• Only assign Issues to Sprints from the Rapid Board