Hi, i develop and publish an application that is compatible only for iPhone, but the App Review test the application also on iPad, and then reject the application, then how is possible?

Hi, I recived for my app the following rejection with a comment: We discovered one or more bugs in your app. Specifically, the “Login” button was unresponsive. I attached the screenshot, here. As you can see from the screenshot the login button is Responsive... but why App Review say not?