Mine fell out from the inside also but didn't break. Stuffed it with a sheet aluminum foil for a few weeks then cleaned up all the cheap, old factory adhesive and reinstalled with 3M automotive double back tape...the kind they used to use to install the badges and door trim, etc. on new cars. Hasn't fallen out again yet. You can get that stuff at a higher end auto parts store like NAPA or pay 3 times that and get it from a car dealer. It will stick anything to anything.
2018 THOR Chateau 35SF
Two Labs, Bugsie & Blondie