What causes a Position Sync to turn off?

Summary:

*Synchronize from Position turning OFF without reason

Content (required):

To my knowledge, all HCM roles are assigned to position sync ON. However, even with this confirmed, I will find many different positions that are turned OFF on the employment page - some that I would have turned on the day before. What reasons could there be for this turning off on its own? I have been advised by the team all roles are on, so what functions or changes cause this to go to "no"?

Thanks for any insight - a new user.