Hello all. We are encountering a problem with the "relay response" of a SIM transaction. (We are aware that SIM is deprecated and are planning a new integration, but in the meantime we need this to function.)
Our logs show that we were receiving relay responses as of Tuesday, and we have not changed our configuration or code since then.
Even though the charge shows up as successful in our transaction log, we no longer see any connection in our server log, not even a 4xx or 5xx error.
A check with iptables verifies that we are not filtering anything in the 198.241 range.