I had a 2017 Chateau 23U and now have a 2018 Chateau 31E, and they both had the mud flap issues. It's a terrible design -- just a couple of small screws that hold the bracket to the sidewall on one side. Those screws rip out and the flap rubs on the tires. I used zip ties from a hole in the flap to the frame to keep them from being pushed back into the tires, and I reinforced the mountings to the sidewall using more/bigger screws and gorilla tape.
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