Are you using Firefox as your browser?
I'm using Firefox ESR and have noticed the same thing. For a month or two or so prior to that, for wife and for me, an attempt to print a donation receipt would print only half of the receipt, apparently due to a bug in the site software. I considered the change to printing the whole receipt in a rotated orientation to be an improvement.
If you plan to report the orientation issue, I suggest clearing your browser cache and deleting relevant cookies and then duplicate the problematic behavior. Otherwise, the first response to your report will be an instruction to clear your cache and delete cookies.