Just sharing my experience here, which is consistent with previous posts from other people.
Last week I topped up my brother's BP using my CC. When I tried to use the same CC (which was already saved in my BP account) to top up my BP, today I got the CVC / Expiry date error, as reported by other users.
I have been using the same CC for both mine and my brother's accounts in the past even after the app update and when other people were reporting about the "CC can only be used on one account" in this thread. I assume that this means the new rule is being rolled out progressively, so everyone will eventually be on this new system. If you're still able to top up more than 1 account, don't be surprised if you suddenly can't anymore.
Upon contacting CS, they stated that this is a new security measure whereby a CC can only be used on one BP account, as there had been many cases of abuse by people using the same CC on multiple BP accounts. CS stated that once a card has been saved onto the BP account, it will not be able to be used on other BP accounts. He also advised that we should use our own CC for topping up BP, and if we want to "top-up" for others, we are free to use P2P.
Going forward, I'll be abiding by this new rule and only use my CC for topping up my own BP account. Hope we won't see further tightening of CC top up....
Probably banks noticed a pattern of large withdrawals from one single card and complained to Bank Negara. It’s no fun for the banks to keep topping up cash in the ATMs since it costs money (security and logistics) not due to the “normal” withdrawal pattern. It’s probably one way for BP to reduce such act. I’m not surprised if more of such rules being applied in the near future.