Hi, @webtoffee
Czech Language.
Here’s a Screenshot of the default template that shows the two strings that don’t get translated. As you can see, the rest of the strings below “Subtotal” get translated.
Actually, some strings are translated in the PDF even when the option is locked behind the Pro version. E.g. the “Delivery” and “Order discount” strings are locked behind the pro version but they are translated by default anyway. Looks like the “Subtotal” and “Payment method” strings are the only ones that don’t get the default foreign translation in the actual PDF.
All strings are translated in your .PO files, and even the page for customising the PDFs is translated (e.g. the Payment Method in the menu), but the actual strings in the PDF are unfortunately always in English.