Client continuously refreshes

Hi,
I have a deployed app at:
https://www.piperouter.com/

It refreshes continuously. So it is unusable.
cat /var/log/nginx/app.log gives:

105.13.225.231 - - [16/Mar/2017:15:42:42 +0000] "GET / HTTP/2.0" 200 1489 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:43 +0000] "GET / HTTP/2.0" 200 1489 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:46 +0000] "GET /sockjs/info?cb=xf84xly7tj HTTP/2.0" 200 321 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:46 +0000] "GET /favicon.png?v1 HTTP/2.0" 304 229 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:48 +0000] "GET / HTTP/2.0" 200 1489 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:48 +0000] "GET /sockjs/332/lfh51a7x/websocket HTTP/1.1" 101 518 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:50 +0000] "GET /sockjs/info?cb=7m6_8sq7p4 HTTP/2.0" 200 321 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:51 +0000] "GET / HTTP/2.0" 200 1489 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:51 +0000] "GET /sockjs/654/jcnz6f66/websocket HTTP/1.1" 101 514 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:52 +0000] "GET /sockjs/info?cb=yqbld_pjnh HTTP/2.0" 200 321 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:54 +0000] "GET / HTTP/2.0" 200 1489 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:54 +0000] "GET /sockjs/073/ozse00ph/websocket HTTP/1.1" 101 514 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:55 +0000] "GET /sockjs/info?cb=dxji6o05nr HTTP/2.0" 200 320 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:57 +0000] "GET / HTTP/2.0" 200 1489 "https://www.piperouter.com/" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
105.13.225.231 - - [16/Mar/2017:15:42:57 +0000] "GET /sockjs/542/dn6m50s7/websocket HTTP/1.1" 101 513 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"

My systemd env is:

NODE_ENV=production
MONGO_URL=mongodb://localhost:27017/TESTAPP_NAME
ROOT_URL=https://piperouter.com
PORT=8080

I think it has to do with mongo. On ubuntu 16.04, my mongod.service is

[Unit]
Description=High-performance, schema-free document-oriented database
After=network.target

[Service]
User=mongodb
ExecStart=/usr/bin/mongod --quiet --config /etc/mongod.conf

[Install]
WantedBy=multi-user.target

I installed it like so:

apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927
echo "deb http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.2 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.2.list
apt-get update
apt-get install -y mongodb-org

My /etc/mongod.conf is:

storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true

systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log

net:
  port: 27017
  bindIp: 127.0.0.1

My /etc/nginx/sites-enabled is pretty standard:

server_tokens off;

map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
}

server {
  listen [::]:80;
  listen 80;
  server_name piperouter.com www.piperouter.com;
  return 301 https://$server_name$request_uri;
}

server {
  listen [::]:443 ssl http2;
  listen 443 ssl http2;

  access_log  /var/log/nginx/piperouter.log;
  error_log  /var/log/nginx/piperouter.error.log error;

  include snippets/ssl-piperouter.com.conf;
  include snippets/ssl-params.conf;

  server_name _;

  location = /favicon.ico {
    root /home/piperouter/bundle/programs/web.browser/app;
    access_log off;
    expires 1w;
  }

  location ~* "^/[a-z0-9]{40}\.(css|js)$" {
    root /home/piperouter/bundle/programs/web.browser;
    access_log off;
    expires max;
  }

  location ~ "^/packages" {
    root /home/piperouter/bundle/programs/web.browser;
    access_log off;
  }

  location / {
    proxy_pass http://localhost:8080;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_set_header Host $host;
  }

}

Any ideas what might be causing the continuous refresh?

On my other devices the app works without any problems.
I cleared the cache on my development browser and now it works there as well.

Solved (afaik)