I have replaced three of these locks. Two on my old MH and one on this one about 6 months after I bought it.
Since then I give the latch mechanism and the metal latch on the door a shot of silicone spray every other month or so to try to keep it moving freely.
Don't know exactly what is causing them to break, (besides cheap components), But knock on wood I haven't had any problems since.
2014 Georgetown 351DS
3 Boston Terriers, 1 Frenchie
Gonna miss you Toby. RIP