I do not know if the 2010-2013 LR4 is identical to the LR3, but if so the shifter cable runs down under the center console pretty much in the center of the vehicle and forward toward the front end by 2-3 feet. There is a heat shield that is easy to remove under this area.
The cable has a tension "aparatus" or connection piece that holds it firmly onto another piece that changes the gears on the transmission. This piece can possibly become loose allowing for the cable to slip, but it is an easy fix. If you crawled under the LR4 and took off the shield it should be mostly self explanatory.
EDIT: I added a blurry photo of the gear selector cable that you can see when you remove the heatshield directly under the very front of the console area under the vehicle.
Where my finger it touching (the rust colored piece) is the part that "grips" the cable and connects it to that angled armature that rises above the cable in the photo. That angled piece is bolted to the transmission and essentially all the cable does is "click" that piece from slot to slot. If you remove the cable you can move it through all the gears by hand under the vehicle. This is where I would look to see if anything is not fully tightened.
Again, I am not 100% if there were any changes from the LR3 to LR4 with this setup. Others may be able to confirm this.