issues communicate with Jetpack!

Hello;

for the past 5 days now, am having issues with jetpack, it has refused to connect properly with my site, other sites on the platform works properly except that they don’t use external DNS. below is the error.

`SELF:
Array
(
[headers] => Requests_Utility_CaseInsensitiveDictionary Object
(
[data:protected] => Array
(
[server] => nginx
[date] => Sat, 04 Aug 2018 16:53:37 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.ams _dfw
[strict-transport-security] => max-age=15552000
)

)

[body] => {“error”:”Unknown Error”,”error_description”:”An unknown error has occurred.”}
[response] => Array
(
[code] => 400
[message] => Bad Request
)

[cookies] => Array
(
)

[filename] =>
[http_response] => WP_HTTP_Requests_Response Object
(
[response:protected] => Requests_Response Object
(
[body] => {"error":"Unknown Error","error_description":"An unknown error has occurred."}
[raw] => HTTP/1.1 400 Bad Request
Server: nginx
Date: Sat, 04 Aug 2018 16:53:37 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.ams _dfw
Strict-Transport-Security: max-age=15552000

{"error":"Unknown Error","error_description":"An unknown error has occurred."}
[headers] => Requests_Response_Headers Object
(
[data:protected] => Array
(
[server] => Array
(
[0] => nginx
)

[date] => Array
(
[0] => Sat, 04 Aug 2018 16:53:37 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.ams _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://healthable.org/xmlrpc.php
[history] => Array
(
)

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

)

)

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

)

The page I need help with: [log in to see the link]