Employee paid under multiple payroll relationships

Summary

Employee promotion closed out previous payroll relationship but employee was under both payroll relationships.

Content

We had an employee who was promoted to a different department and had a change in their paygroup. This change closed out their previous payroll relationship - However they were paid under both paygroups.

Only after updating the end date for the previous payroll relationship the payroll stopped getting calculated for the previous assignment.

Is there a configuration change needed or did this have to be a combination of a transfer and a promotion?