Sorry reading this happened. Just curious, can you post a photo of your fifth wheel? I've had two fifth wheels now and have been towed them with no problems. My first hitch was a slider but I never had to use it. I started having some play in one of the rails so I purchased a new non-sliding hitch. I think the problem people are having is due to the cap on the fifth wheel. To be honest, if I had a problem like this I would have a slider.
Took some time today and looked at your fifth wheel, and yes I would have a slider.