Thanks for the report. You may notice when creating brand new boards, that the amount of padding between the edge of the note and the text has been slightly increased. In a setup like this where there is no border, you wouldn’t really notice that, but when comparing older boards to new ones, it should be fairly obvious.
Old boards have their existing padding amount protected, as a form of backward compatibility, as otherwise you could find whole layouts damaged by the change. That the board looks fine before you print it is proof of that—but unfortunately it looks like that compatibility layer was omitted for printing/export!
By the way, you could get around the bug for now by “upgrading” your board. Make a new one from scratch and drag and drop the notes over into it. You’ll note the wrapping problem immediately, just like in the PDF—you can use the Notes ▸ Auto-Fit command to clean up most cases automatically.