I have the same problem. I have a French mastiff which is one of the best breeds in the world but they are stubborn.
She is very smart it only took me a month for her to fully be house broken. My problem now is when I pay attention
To my cat she will pee in front of me then run away. If she got in trouble earlier that day, when I leave she will pee in
The house. If we had a good day and I leave her alone in the house she will not go in the house. People have tried to tell
Me she is not fully house broken, which I know is not the case. Every time she goes Inside I automatically know when she does it because
She will run away from me when I walk through the door. They said to crate train her when I leave. So I made the crate small
Enough to where she could only turn around in. I was told that if I did this a dog would not have an accident in the crate because
Dogs don't like to be in their feces. When I came home she was laying In her pee and had poop all over her belly. What stunned me
Was that she actually pulled the tray from under her and poked and peed on the actual floor! Every time she ever went in the house I
Made sure I put that pet odor Eliminator on the floor so it's not like she smelled her scent on the floor to make it seem like it was OK to
Urinate on my floor. So I decided to put her outside all day and show her no attention. That just made it worse! She started urinating all the time
In the house so I know it's a behavior problem. It seems like I'm having a bate with my own dog. I need help I have no clue what to do. But like they say French mastiffs are stubborn dogs

Judy, I can tell from your post that you are frustrated. Sorry to do this but please give us a bit more information so we can offer the appropriate advice.

1. How old is the dog?
2. How long have you had her?
3. Is she spayed?
4. How much exercise, & attention does she receive each day?
5. When she urinates on the floor in front of you, how do you correct her?
6. When you come home and find the mess she has made, do you correct her, and if so, in what way?
7. You mention "she got in trouble earlier in the day". What exactly does that mean? Just urination? Or is she doing something else & if so, how are you correcting her behavior?

I also have a French Mastiff. Same problem. She's house broken but pees in the closent and then when she sees me she has her tail tucked under her and knows she's done wrong. Its attention. This breed bonds strongly with their master/family. If you do not pay attention to the dog the only way it can tell you about it is to pee - to do something she knows you don't like. To get your attention. If we leaver her inside and go outside to play without her she will pee. She's mad. Very lovable breed and needs her family. We've been gone a lot lately and that's when it started. Again, I've read a lot about the breed and figured out its just her way of telling me that she needs more attention. That's the type of dog she is, loyal. And because of her ferious loyalty she expects it back from me! Hope that helps.