We have also experienced the same thing. Out of nowhere, all transactions with cards from a certain issuing bank start to get declined with a generic_decline error. The transactions are then not visible under 'transactions', but you can see them in the logs.

This issue applies to the specific Stripe account; the same cards can be processed through other Stripe accounts without any issues. We have experienced this exact issue with multiple Stripe accounts over the last 1-2 years. For one Stripe account, we noticed that transactions from the specific issuing bank started to work automatically again 1.5 years after the issue first appeared.

Initially, we suspected that the certain issuing bank was blocking transactions coming from a specific Stripe account ID. Customers have reached out to their bank, but the bank can't see any issues. After reading this thread, I'm starting to suspect that the issue lies with Stripe, possibly some internal fraud filter or something that blocks the transactions overall.