Hello Harry,
I have a multilingual site English and Arabic, I was testing the flow of the user in the Arabic version of the site and everything went fine except in the checkout page postcode and phone fields.
so I filled all the fields name and address in Arabic and when I tried to fill the postcode and phone it gave me errors that they are incorrect.
I tried to switch my keyboard input to English and use numbers like this (123456789) instead of the eastern Arabic numbers (١٢٣٤٥٦٧٨٩) and it worked fine.
so it seems that the user can not input these eastern Arabic numerals which gonna be confusing for them and they might quit the page.
I hope you can tell me what should I do because it is very important.
kind regards