Unfortunately, NFC technology for contactless payments has not yet been fully introduced at all acceptance points worldwide.
When problems occur, this is often at "unattended terminals", e.g. beverage machines, toll systems or cash desks in car parks. Here, individual or sometimes even all cards can be temporarily rejected.
When attempts to pay without contact are rejected, please insert the card into the reader as far as possible or use a different method of payment.
Please also check this article to understand contactless limits.