You are entering the wrong combination. Code enter into the lock may not be registering proper.
Safe Bolt work damage. Fired Safe Re-locker.
End or Side pressure from the safe bolt work. Spindle is too long.
The spindle length is to long. Parts of the keypad are rubbing against each other and causing friction.
The Yellow, Blue or Black tab is out of alignment with the metal notched baseplate.
This could be an indication that the lock has an electronic short.