Most browser will use the last setting print as the printing options. It sounds more like a print settings when firefox was installed that it wasn't set or changed during that time. I doubt chrome does that as it prints with the last printed setting each time. I have yet to see it do something like your asking unless the user changes it each time they print. And I have IE, Edge, Chrome, Firefox installed and use them as needed.

In Chrome the pdf is automatically adjusting to print the pdf to landscape and portrait Depending on the Pdf you are printing .if it is landscape it is automatically adjusting to print Landscape & if it is portrait it is adjusting and printing portrait.

One has to remember how chrome implements pdf printing options isn't going to be the same for firefox. So where are you referring to the pdf that does that? I like to see if what your saying is doing that as well? But it has to be public pdf if this is login pdf site then that will be harder to know what is happening.