invalid response from the jetpack site

Suddenly I’m unable to post photos to my wordpress site from the iOS app. I get the following error when I try:

“invalid response from the jetpack site”

when I do the debug, it says Jetpack is having problems communicating with the site. The output from that is the following:

SELF:
	Array
(
    [headers] => Requests_Utility_CaseInsensitiveDictionary Object
        (
            [data:protected] => Array
                (
                    [server] => nginx
                    [date] => Sun, 16 Oct 2016 19:34:33 GMT
                    [content-type] => text/plain;charset=utf-8
                    [expires] => Wed, 11 Jan 1984 05:00:00 GMT
                    [cache-control] => no-cache, must-revalidate, max-age=60
                    [x-hacker] => Jetpack Test
                    [x-ac] => 3.dca _dca
                    [strict-transport-security] => max-age=15552000
                )

        )

    [body] => {"error":"Communication error","error_description":"We were unable to make an XML-RPC request to your website. Please make sure that XML-RPC is turned on and that Jetpack is installed, activated and connected with your WordPress.com account. If the error persists, try disconnecting and connecting Jetpack again."}
    [response] => Array
        (
            [code] => 400
            [message] => Bad Request
        )

    [cookies] => Array
        (
        )

    [filename] => 
    [http_response] => WP_HTTP_Requests_Response Object
        (
            [response:protected] => Requests_Response Object
                (
                    [body] => {"error":"Communication error","error_description":"We were unable to make an XML-RPC request to your website. Please make sure that XML-RPC is turned on and that Jetpack is installed, activated and connected with your WordPress.com account. If the error persists, try disconnecting and connecting Jetpack again."}
                    [raw] => HTTP/1.1 400 Bad Request
Server: nginx
Date: Sun, 16 Oct 2016 19:34:33 GMT
Content-Type: text/plain;charset=utf-8
Transfer-Encoding: chunked
Connection: close
Expires: Wed, 11 Jan 1984 05:00:00 GMT
Cache-Control: no-cache, must-revalidate, max-age=60
X-hacker: Jetpack Test
X-ac: 3.dca _dca
Strict-Transport-Security: max-age=15552000

{"error":"Communication error","error_description":"We were unable to make an XML-RPC request to your website. Please make sure that XML-RPC is turned on and that Jetpack is installed, activated and connected with your WordPress.com account. If the error persists, try disconnecting and connecting Jetpack again."}
                    [headers] => Requests_Response_Headers Object
                        (
                            [data:protected] => Array
                                (
                                    [server] => Array
                                        (
                                            [0] => nginx
                                        )

                                    [date] => Array
                                        (
                                            [0] => Sun, 16 Oct 2016 19:34:33 GMT
                                        )

                                    [content-type] => Array
                                        (
                                            [0] => text/plain;charset=utf-8
                                        )

                                    [expires] => Array
                                        (
                                            [0] => Wed, 11 Jan 1984 05:00:00 GMT
                                        )

                                    [cache-control] => Array
                                        (
                                            [0] => no-cache, must-revalidate, max-age=60
                                        )

                                    [x-hacker] => Array
                                        (
                                            [0] => Jetpack Test
                                        )

                                    [x-ac] => Array
                                        (
                                            [0] => 3.dca _dca
                                        )

                                    [strict-transport-security] => Array
                                        (
                                            [0] => max-age=15552000
                                        )

                                )

                        )

                    [status_code] => 400
                    [protocol_version] => 1.1
                    [success] => 
                    [redirects] => 0
                    [url] => Requests_IRI Object
                        (
                            [scheme:protected] => https
                            [iuserinfo:protected] => 
                            [ihost:protected] => jetpack.wordpress.com
                            [port:protected] => 
                            [ipath:protected] => /jetpack.testsite/1/
                            [iquery:protected] => url=https://www.justincamblin.com/xmlrpc.php
                            [ifragment:protected] => 
                            [normalization:protected] => Array
                                (
                                    [acap] => Array
                                        (
                                            [port] => 674
                                        )

                                    [dict] => Array
                                        (
                                            [port] => 2628
                                        )

                                    [file] => Array
                                        (
                                            [ihost] => localhost
                                        )

                                    [http] => Array
                                        (
                                            [port] => 80
                                        )

                                    [https] => Array
                                        (
                                            [port] => 443
                                        )

                                )

                        )

                    [history] => Array
                        (
                        )

                    [cookies] => Requests_Cookie_Jar Object
                        (
                            [cookies:protected] => Array
                                (
                                )

                        )

                )

            [filename:protected] => 
            [data] => 
            [headers] => 
            [status] => 
        )

)

Does this shed any light on my issue?

The XMLRPC server seems to be functioning for my site. Here's the output when I load it.

XML-RPC server accepts POST requests only.

Thanks.