Drivers door sticking

[Gramwam]

My drivers door is sticking from the inside whilst using the handle, needs a good shoulder shove. It works perfect from outside. Central locking is fine from the fob and the inside switch.

Any advice welcome. Am I missing something obvious?
Easy fix, do not fancy stripping the door.

I have seen posts about the door being stuck from the outside but not many from the inside.

Thank you.