ERR_CONNECTION_TIMED_OUT после dokku letsencrypt myapp.mysub.mydomain.net

Сайт работал нормально, пока я не попытался активировать letsencrypt.

Похоже, он установлен без проблем.

dokku letsencrypt myapp.mysub.mydomain.net
=====> Let's Encrypt myapp.mysub.mydomain.net
-----> Updating letsencrypt docker image...
latest: Pulling from dokkupaas/letsencrypt-simp_le
Digest: sha256:398e9173f8e9662df66cb6d0dfa6c6ac07f1e3d65b7994177d487d36eb9b10be
Status: Image is up to date for dokkupaas/letsencrypt-simp_le:latest
      done updating
-----> Enabling ACME proxy for myapp.mysub.mydomain.net...
-----> Getting letsencrypt certificate for myapp.mysub.mydomain.net...
       - Domain 'myapp.mysub.mydomain.net'
darkhttpd/1.12, copyright (c) 2003-2016 Emil Mikulic.
listening on: http://0.0.0.0:80/
2017-01-29 19:19:28,060:INFO:__main__:1305: myapp.mysub.mydomain.net was successfully self-verified
2017-01-29 19:19:28,156:INFO:__main__:1313: Generating new certificate private key
2017-01-29 19:19:29,577:INFO:__main__:391: Saving fullchain.pem
2017-01-29 19:19:29,578:INFO:__main__:391: Saving chain.pem
2017-01-29 19:19:29,578:INFO:__main__:391: Saving cert.pem
2017-01-29 19:19:29,578:INFO:__main__:391: Saving key.pem
-----> Certificate retrieved successfully.
-----> Installing let's encrypt certificates
-----> Unsetting myapp.mysub.mydomain.net
-----> Unsetting DOKKU_NGINX_PORT
-----> Setting config vars
      DOKKU_PROXY_PORT_MAP: http:80:5000
-----> Setting config vars
      DOKKU_PROXY_PORT_MAP: http:80:5000 https:443:5000
-----> Setting config vars
      DOKKU_NGINX_PORT: 80
-----> Setting config vars
      DOKKU_NGINX_SSL_PORT: 443
-----> Configuring myapp.mysub.mydomain.net...(using built-in template)
-----> Creating https nginx.conf
-----> Running nginx-pre-reload
      Reloading nginx
-----> Configuring myapp.mysub.mydomain.net...(using built-in template)
-----> Creating https nginx.conf
-----> Running nginx-pre-reload
      Reloading nginx
-----> Disabling ACME proxy for myapp.mysub.mydomain.net...
      done

Нет ошибок в файлах журнала приложений nginx или dokku.

Я погуглил ERR_CONNECTION_TIMED_OUT after dokku letsencrypt без удачи. Есть указатели на информацию об устранении неполадок?

Я могу восстановить доступ к сайту только после отзыва и очистки.