I recently got a Mercury Card VISA card, confusingly issued by First Bank and Trust. It showed up in the list of participating institutions, and successfully set up one-step updates.
But a weird thing I've never seen before happens every time: every charge transaction is downloaded as a payment, and all payments are shown as charges. I'm thinking it's a function of how Mercury simply displays their transactions. In a chat with their tech support, they say they have no idea how Quicken downloads their data, and could offer no help.
Any ideas? I think they are a relatively new card issuer.