Can't end an assignment the day before the new assignment starts

Hi,

We are experiencing an issue when attempting to end the first assignment of an employee who has two assignments.

The first assignment is permanent and their second assignment has been setup as temporary.

The employee's first assignment should end on the 25th of August 2025. Their second assignment starts on the 26th of August.

We were initially experiencing issues with them having multiple primary assignments and multiple primary work relationships, these issues have now been solved.

The current problem we are having is that we are not able to select the action of "End Assignment" when attempting to end their assignment on the 25th of August. It is just not in the list of values to select.