Your ignition switch maybe binding or in need of replacement.
1st try reading my post on loosening/freeing and stuck ignition lock cylinder.
If that doesn't work, you probably need to replace the ignition cylinder which runs about $70 bucks online OEM.
Have a locksmith key it for you.
You can also remove the lock cylinder quite easily.
1. Remove your battery ground wire.
2. Turn the ignition key to the ON position (clockwise turn of the key)
3. Now look under the steering column near the lock cylinder and you'll see a hole in the plastic bezel.
4. Take a narrow Phillips screwdriver and feel for the pin that will release the cylinder.
5. Depress the pin while pulling out the cylinder.
6. check for free movement of the cylinder and lubricate thoroughly.
7. If the cylinder turns freely, you probably have a linkage issue within the steering column causing the issue. That will be expensive and out of my league on how to repair.