Yes. My girl is the same way. Unfortunately, if you don't catch them in the act there's nothing you can say otherwise you could make her think going to the bathroom in general is a bad thing. I know when Sienna is wandering around and not in the same room we try to keep one eye on here. Any signs she might have to go such as sniffing the floor it's right outside and we will wait until she goes. Also, after she eats or has a play session or a nap it's right outside. When she goes pee it's lots of praise and a treat - I keep one in my pocket. If I'm lucky enough to catch her in the act of peeing on the floor it's a firm no, then I move here right outside and tell her to go pee. If I see her at the door I tell her she's a good girl, open the door and tell her to go pee. This is our first mastiff but we have a lot of experience with pups in general and it's pretty much the same with all of them. However, it doesn't matter how perfect or imperfect the system is, puppies are always going to have accidents. The key is to stay firm and consistent.