Well there are various reasons why a door handle might stick.
Why door handles stick.
A sticking door latch might require some lubrication or it might be jamming against the strike plate on the door jamb.
To test this firstly open the door and check that there are no obvious obstructions on the tubular latch plate such as loose screws or signs of internal parts of the latch or lock poking through.
You should first test the door latch to ensure the latch is sticking inside the door and not due to a misaligned strike plate.
The striker plate might be out of adjustment causing the striker to catch and become stuck.
Loosen up an uncooperative doorknob by lubricating the inner mechanism.
Turn the knob to open the door and release the knob slowly.
And it largely depends on just a few things as follows.
The most common cause of sticking door handles is some kind of malfunction within the tubular latch itself.
Sticking door locks can be attributed to everything from slight settling of the house to a buildup of dust and dirt within the locking mechanism.
Escaping inclement weather with an armful of groceries becomes frustrating when a sticking door handle denies you access.
Fortunately most front door lock problems can be.
In some instances you have a door that sticks along the strike area the metal part of the door frame where it meets the outermost edge of the door.