Ok, I was able to get my slide in thanks to the tip offered in this video.
I held the retract button until it stopped. Then I touched the extend button until I heard the motors than I pressed the retract button again. My slide came all the way in.
I repeated this twice to make sure it worked.
My slide does stop once upon retracting. I really think there is still an issue but I am able to get it all the way in by following the procedure in the link.