I can't find a source for this, but have it on good authority from a contact in the payments space, that Discover (in their role as a card-issuing bank) has rec

I can't find a source for this, but have it on good authority from a contact in the payments space, that Discover (in their role as a card-issuing bank) has recently begun an absurdly merchant-unfriendly practice of automatically initiating chargebacks, based on their own behavioral analysis systems, unilaterally bypassing the otherwise-standard practice of awaiting the cardholder's confirmation that a transaction is fraudulent/unintended before initiating a chargeback. And since every single chargeback is immediately deducted from merchant accounts and adds to an opaque counter that, when tripped, can cause the merchant to be effectively blacklisted by all reputable acquiring banks... you're basically placing your company's future in the hands of Discover's algorithms. With a business like Digital Ocean's that is already dealing with fraudulent cards being used for crypto mining, they're almost certainly treated especially harshly by said algorithms, and are wildly conscious of that blacklist. I'm not at all surprised that their operations team has pulled the plug on Discover even before updating the UI of supported cards.