My puppy stopped peeing outside?

Ivory is my 5 month old Doberman puppy a she used to be potty trained perfectly. I taught her to scratch my door and wait for me the moment she needed to pee or anything and she was doing absolutely wonderful but now she pees inside. She still poops outside but she completely reverted and doesn’t pee outside. I know why tho but I wonder why she stopped asking for my help. She’s to big for our doggy door which is why I never taught her to go though the doggy door and to grab me. She would anyways but now she is too big cus it was made for our small dogs. I don’t understand why she stopped scratching or telling me that she needs to go pee tho? I know she’s terrified of my grandma but she is 100% safe with me so I’m guessing she’s scared? Cus my grandma will sometimes leave her outside until my grandma decides she wants her back so I definitely think it’s fear related but I always go outside with her. Idk I need help and advice. Do I retrain her completely again?