Hi @KirbyHawk75 probably just a sudden urge and accident. Don't get alarmed. Just go back to positively rewarding her defecating in the garden. Yes then treat.
Could be the ‘teenage’ type period I’ve heard about a few times, forgetting, defiance etc maybe. Our friend has a 9 month old who went through a short faze of weeing in the house and just staring at them as if to say ‘what you gonna do about it’ kinda thing ha ha! Seems a lot of pups go backwards slighty around this age, I’m not looking forward to it. Back to basics probably.