Samsung SHS P718 activates deadbolt after opening

My SHS P718 digital door lock isn't a padlock, but that is the closest device I found in the list to submit this question.

It has recently begun activating the locking operation with the door wide open all by itself. I have to then unlock the deadbolt, so it can retract; in order to close the door.

I've used compressed air to clean out the triangular sensor below the deadbolt, but that has not helped. Any suggestions from anyone?