I had a problem for a couple of weeks that my floor shifter was really hard to shift and I had to shift past "D" then back to "D" to engage drive,
and the lockout button on the shifter handle would not depress. I had to press the little plastic lever at the bottom right of the shifter shaft under the boot
to get the shifter to move and the car to start.
Then suddenly one afternoon, I shifted into park(or so I thought) and the Jimmy started to roll and I could not get my key out after shutting down.
So, I figured it could be any one of a number of electronic items connected to the shifter but first I wanted to check the shifter linkage.
I could move the shifter on the side of the transmission by hand into park and back into reverse no problem but when I did this, the cable inside
the cab, at the shifter, hardly moved. I figured the cable wasn't broken because I was able to get the Jimmy in gear by moving the shifter, it's just that
nothing was lining up. Park was reverse, it wouldn't go into drive without first going past drive.....

What I found out was, the cable was kinked.
apparently, when I reinstalled the skid plate to the 4WD transfer case, I pinched the shifter cable and caused it to stretch and kink.

I hope this helps.

 

Mine is a column shift; but I did go down below this thread and look at Related Topics, try that and see if one of those treads will help you.
L