I’ve also have experienced this. Even when the page size is set to “Letter”, when saved as a PDF, the dimensions become 9.653" x 12.487".
It hasn’t been a huge problem, as printing with “Fit to Page” selected prints just fine… But if “Actual Size” is selected, some of the document gets runs off the page and clipped.
I just tried a clumsy workaround that worked, but I’m hesitant to rely on it :grinning_face_with_sweat: …
In my case, at least, both the length and width are off by the same ratio. 8.5 is approximately 88% of 9.653, and 11 is approximately 88% of 12.487.
By that scale, if I want to export a page at 8.5" x 11", I should set the page designer dimensions to 7.48" x 9.69". I chose a custom page size in Page Designer, and converted those dimensions into pixels (looks like 1" = 109px).
I set the dimensions to 816px by 1056px, and then saved the page as a PDF. To my surprise, it exported as 8.5" x 11"!
Not sure if this is repeatable… but it’s worth a shot, maybe? Good luck!