I bought 5 paypower debit cards in one grocery store with CC, with no issues.
the second day, I came in to buy another 5, and after swiped my credit card, the cashier told me these cards failed to activate, and had to refund my CC.

Probably because these cards are "cash only", and paypwoer somehow detected my purchased using CC one day ago? What could be the reason that the cards not vitiated?