It’s necessary that a deadbolt fully extends when retracted. Otherwise, the door doesn’t properly lock and poses a security risk. If you are facing resistance when turning the bolt it could be due to interference with the strike plate.
The problem can be resolved by correctly aligning the strike plate with the faceplate. Misalignment can be caused by sagging of the door. Therefore, it’s suggested that you inspect the hinges and check if the door is properly hung before making any adjustments.