Seems to be a more general problem: I have those WARN messages when remotely connecting via Android App:
2017-01-06 11:46:02.664 [WARN ] [io.openhabcloud.internal.CloudClient] - Jetty request 89017 failed: null
2017-01-06 11:46:08.836 [WARN ] [io.openhabcloud.internal.CloudClient] - Jetty request 89025 failed: null
2017-01-06 11:46:11.089 [WARN ] [io.openhabcloud.internal.CloudClient] - Jetty request 89021 failed: null
2017-01-06 11:46:11.520 [WARN ] [io.openhabcloud.internal.CloudClient] - Jetty request 89035 failed: null
I have seen those messages since the first day of changing from my.openhab to openhab cloud connector, currently on build #684