Clearly you're not reading the posts, as your solution has been tried and still occurs when Payees are setup in the same currency, as well as in incognito/inprivate sessions. I've even contacted customer support as you suggest, and they say to schedule a call, but then no one ever calls me. 

FOR OTHERS FACING THIS PROBLEM:

I have found a solution that works (at least for me), if you setup your vendor/payees (Wells Fargo and Citi Bank for me), then in the Record Credit Card Payment screen, you can type out the full name of the Payee and hit Tab, the result will stay and be check marked, allowing you to actually select it even though it fails to do so in the dropdown.