Door not fully unlocking

[Callum 13 1 Cars]

I have an issue with my drivers door lock mechanism, the door pin keeps seizing from coming fully up when the car is unlocked which stops the door unlocking. I have a central locking fob and when I press unlock button all the car locks unlock then lock straight away and when I use the key in the driver lock it moves freely but doesn't turn enough for the door pin to come up fully. There isn't an issue with the lock as once the door pin is freeid it's works fine any idea what it is that is seizing up? 

Edited January 27, 2020 by Callum

[steve@cornwall 100]

Return on door handle itself. You may be licky and spraying the back of the handle from within the door and giving the handle many "jiggles" 

More likely its going to need to take the handle off. Once off it becomes obvious