The driver's side door won't latch shut.
From the description provided it appears that the door latch is stuck open or perhaps stuck in the closed position. The door latch receives a lot of use and over time if not properly lubricated, can become stuck in a position and sometimes fail. It may also be possible that the door has become misaligned and simply needs to be adjusted for the door latch to function properly. I recommend enlisting the assistance of a certified mechanic to come by and inspect your door in person for the best diagnosis. They will have the experience to quickly determine why your door will not latch shut and decide if it is a matter of a simple adjustment, they can make it right there on the spot. If the culprit is a faulty door latch, they will be able to perform the repair needed to allow you to close your door properly.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing