Hi Alyssa,
This is because "Planning" equates with "Planning" in the Project Statuses setups.
The answer depends on why you are putting projects back into planning....is it intended that you are just changing some of it but you want the existing tasks to remain in execution? If so, it might be better to create a new status (e.g. Execution + Planning Changes) and set this to equate with "Current" which means that the users will still see their assigned tasks as active tasks.
Hope this helps.
Cheers, David.
