Google "fifth wheel pin box failure", or cracks, damage, etc. and there is a lot of info. on this. More common problem than you would think. Better do an inspection and repair as needed before it's too late.
We've experienced a serious Lippert frame issue before, but not on a FW. They continue to build TT & FW frames that are structurally inadequate and poorly put together. The real problem is the total lack of any industry standards and they can build whatever they want, however they want without answering to anyone.
The best thing to do would be to take it to a frame & axle shop that has a lot of experience with RVs. In BC we have gov't "designated inspection facilities" who have to meet gov't standards. If you have that in Ont., I would take it to a frame shop that has that also.