I sat down to write code today and I am experiencing all sorts of gateway timeout 504 return errors with both refunds and charges on multiple sandbox merchant accounts under 2 different logins. This code worked yesterday. In the dashboard the transactions are showing up as Payment Failed. Likewise, the API it is returning HTML content instead of the documented JSON which broke my code so I had to add error handling to my code to test if the response from the sandbox was JSON before I tried to parse it. So the good news is my code is now more robust to failure, but what gives with the sandbox?