Removing direct reports in Add assignment transaction

Hello experts,

we have this issue wherein we created a temporary assignment for a line manager, and all his direct reports from his suspended assignment followed him to his new temporary assignment which is incorrect. The direct reports should've stayed to the suspended source assignment.

We found this in the oracle docs wherein you need to manually remove the direct reports for them not to follow the newly created assignment.

Our question is does the Synchronize Person Assignment from Position process not applicable in the Add assignment page? We thought that since we are running this process everyday, the direct reports will automatically be transferred back to the source assignment even we didn't remove the direct reports in the Add assignment page.