For security, your Fandom Pay card is set-up with contactless counters. This means that you will need to enter your PIN after you make 5 contactless transactions or you spend €150/£125, whichever happens first.
You should be prompted to make a Chip and PIN payment, but as this is a new measure there may be times that the prompt fails. If your payment does not go through, please try making a Chip and PIN payment. Once the PIN has been entered, the contactless counter is reset again.
You will also need to complete a chip and PIN transaction when you first receive the card before the contactless element is activated.