I have a 14week old shihtzu who is paper trained at the moment apart from a couple of accidents, but whenever I go upstairs even for a few minutes, she manages to do a poo next to her pad.
She may have already done a couple of poos earlier but she never fails everytime she is left downstairs.
Night time she is fine as she sleeps in her crate.
She is not allowed upstairs for obvious reasons. I have carpet upstairs.
What are the 'obvious' reasons she is not allowed upstairs? If she is allowed to follow you up there she most likely won't do it. Or you could pop her into her crate if you are going to be up there for a while. My puppies follow me everywhere (even the ten year old ones!). Five small dogs and a GSD in the bathroom makes for a cosy atmosphere! Try taking her out and waiting till she has been before leaving her. By this age she should be learning to go outside.