Problem

Multiple active sprints shown in Agile Scrum board when the parallel sprint option is disabled. As shown below. In Board Sample Scrum Project A, there are two active sprints; SPRINT SSPA 3 and SPRINT SSPB 3.

SPRINT SSPA 3 belongs to Board Sample Scrum Project A. But SPRINT SSPB 3 belongs to Board Sample Scrum Project B.

Diagnosis

Diagnostic Steps

1. Check if the parallel sprint option is enabled or not. If the option is disabled, then multiple sprint is not expected.
   
2. The filter for Sample Scrum Project A is project = "Sample Scrum Project A" ORDER BY Rank ASC
3. Check the issue in the SSPB-9, and refer to the value in the Sprint field.
   
   
   

Cause

Board will be showing issues or sprints based on its filter. The filter of board Sample Scrum Project A is project = "Sample Scrum Project A" ORDER BY Rank ASC. Which means that it will show every issue with issue key SSPA and it will show all sprints that associated with issues SSPA. The reason why sprint SSPB3 is shown in board Sample Scrum Project A is because issue SSPA-9 has the sprint value of sprint SSPB 3. Thus, once sprint SSPB 3 is active in board Sample Scrum Project B, it will appear as active sprint in board Sample Scrum Project A. 

Resolution

If it's not intended for issue SSPA-9 to be in sprint SSPB 3, then it's suggested to disassociate sprint SSPB 3 from issue SSPA-9