Like others have already mentioned, use ZIP ties.
I have had the same issue wit multiple 5th wheels & slides. What I do is drill three holes vertically in the broken pieces and ZIP tie together. This gives them flex. Have not had issues with the latest one that broke over a year ago. You can find replacements on Amazon. Since we camp in cold weather, they break all the time. ZIP ties are the cheapest and apparently most reliable.
Not worth the hassle to me to take to dealer, order parts, wait weeks to have it installed. 10 minutes and three ZIP ties and I have it fixed myself.
2014 Dynamax Trilogy 3850RL - South Hampton Interior, Full Body Paint (Black / Silver / White), MOR/ryde Independent Suspension, MOR/ryde Disc Brakes, ONAN 5500 Generator, Progressive Industries HW50C w/Dual Display, Winegard HD Dish w/DirecTV, Washer & Dryer, iSprings 7-stage Reverse Osmosis Water Filter, Trail-Air Flex Air Pin Box, Third AC installed, AC Voltage/Amp Meters, DC Amp Meter.
Retired USAF - Full Timers!