I have this problem with many of my trailers. The suggestions above are all excellent. I find that the most common problem on mine is when the latching mechanism isn't retracted properly when I let the tongue down, I've also had them slide down when the tongue is dropping down. If it is giving you a lot of grief it may need adjustment.
I ordered my last work trailer with a pintle hook to get rid of this problem. I doubt most TT owners could put up with the jerking sensation you get from a pintle though, and no WD option.
Al, Travelling with wife, daughter 5, son 3, 3/4 tons of 2013 Ram CCLB, five tons of fifth wheel Rockwood 8287SS still showing my kids north america one campground and road trip at a time.