1-yr old still poops in the house at night.

It has never taken me so long to uncrate a puppy! She’s 14 months old, never pees in the house, and never poops in the house during the day. The only exception to this rule is if we let her sleep outside her crate at night, she will poop once in the exact same spot every night. Never does so when she’s crated. All my other puppies were allowed to sleep outside their crates with no messes by 10 months. Why is she doing this? Any tips? I can’t really chastise her for the poop since I find it after I wake up, not when she’s in action. Not sure how to address this but don’t want her in the crate forever. She eats around 7pm and goes outside several times before bed. She is let out again at 6:15 every morning, the routine is pretty exact. Never has been free fed (she eats twice a day quickly and happily) and usually water is up by 9pm (again, peeing is not the problem). We have an older dog in the house too who never has any accidents. Help!