1. Either door itself falls or the door compartment fails to function properly, causing the deadbolt is stuck in a shackle and not operate smoothly.
First, check the operation of the square lock (deadbolt) while the door is open and if there is no problem, you must check the door itself.
Please contact to a professional door company to check the door itself.
2. If the square-locking device (deadbolt) is not operating smoothly while the door is open, please call the service center.