Jetpack won’t connect to site

A few days ago, Jetpack’s publicize feature stopped working completely. I deactivated it and tried reconnecting it, but now it won’t do so. I’ve run through the troubleshoot list and have not found a solution. Here’s the debugging info:

SELF:
Array
(
[headers] => Requests_Utility_CaseInsensitiveDictionary Object
(
[data:protected] => Array
(
[server] => nginx
[date] => Fri, 23 Sep 2016 15:46:46 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.dfw _dfw
[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.”}
[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."}
[raw] => HTTP/1.1 400 Bad Request
Server: nginx
Date: Fri, 23 Sep 2016 15:46:46 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.dfw _dfw
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."}
[headers] => Requests_Response_Headers Object
(
[data:protected] => Array
(
[server] => Array
(
[0] => nginx
)

[date] => Array
(
[0] => Fri, 23 Sep 2016 15:46:46 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.dfw _dfw
)

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

)

)

[status_code] => 400
[protocol_version] => 1.1
[success] =>
[redirects] => 0
[url] => https://jetpack.wordpress.com/jetpack.testsite/1/?url=https://hifinoise.com/xmlrpc.php
[history] => Array
(
)

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

)

)

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

)