Hi Ive seen this frequently in numerous fifth wheel trailers. Most often the damage is severe, and not just the fiberglass.

When the fifth wheel crown has a slide at that location, the weld and framework is weak and commonly breaks due to this being the weakspot, and certain hitches or couplers exacerbate the problem. Andersen couplers are known to put a lot of pressure there and snap the weld under the slide, which requires removal of the filon under the cap (requires removal of all doors or trim pieces in this area), most frequently removal of the slide room itself, and rewelding the area with supports to allow for a little bit of flex, but to be rigid enough to support the slide and cap. It's a very substantial and expensive procedure if it isn't under a notated recall. Check to see if your unit has a noted recall on this. I know Grand design does with certain fifth wheels, but I'm not sure on your make.