Page Orientation issue while printing

Whenever i hit the save as pdf on my firefox browser, it saves the pdf (usign free version) in landscape format. I see that the default is portrait so why am i getting landscape while converting to pdf .

For example i created a pdf of the url below and it came as landscape.

https://growthhackers.com/questions/ama-im-iris-shoor-co-founder-vp-product-takipi-solving-one-cloud-computings-toughest-problems-finding-code-breaks-production

Can anyone use the above url to save it as pdf and see how many pages they get. I get 11 pages. That way I can check if my settings are an issue or others are facing the same issue?

What is the way to fix this?

thanks