Disappearing fences next to roofs

I found this while running into the same issue, but I actually found a little hack for it! I have twisted mexi's TOOL and betterbuildbuy, in case that matters, but I don't think it should. It looks like you're using half hipped roofs and surrounding the platform. Instead, use a hipped roof piece and drag it into the platform so that the peak is still where you would want it. The other half will hide inside the platform, and because the edge of the roof is not against the platform, it doesn't register as roofline. You will still have to use multiple roofs like you're doing in the picture, but by using full roofs instead of half roofs the fences will still appear. 

I hope this helps!!!