Your card may be locked for different security reasons.
Some of the most common ones include typing your PIN incorrectly 3 times or too many consecutive failed transactions, for example, insufficient balance when trying to process a transaction.
If your card is locked because of an incorrect PIN, it will be unlocked automatically at 00:00 Hong Kong time.
If you had successfully updated details in your profile (e.g. change phone number), there will be a temporary 24-hour lock on your Neat Card.