EU/Finland has used debit+credit combination cards over 21 years.

20 years ago the card type caused confusion going abroad, especially US, but also some European countries that had not yet introduced the same card type. Some merchants were confused about the extra prompt about which card to use before the customer enters the pin.

But it has worked fine 99% of exotic places. I think the 3D secure caused much more trouble when shopping online when it was introduced compared to the choice of using either the debit vs credit variant online.