try without pm2

demo-server/demo-server.js

@@ -21,6 +21,6 @@ const wss = new WebSocket.Server({ server })
 
 wss.on('connection', (conn, req) => setupWSConnection(conn, req, { gc: req.url.slice(1) !== 'prosemirror-versions' }))
 
-server.listen(port)
+server.listen(port, '0.0.0.0')
 
 console.log(`Listening to http://localhost:${port} ${production ? '(production)' : ''}`)

fly.toml

@@ -14,7 +14,7 @@ swap_size_mb = 0
   force_https = true
   auto_stop_machines = true
   auto_start_machines = true
-  min_machines_running = 0
+  min_machines_running = 1
   processes = ["app"]
   [http_service.concurrency]
     type = "requests"

package.json

@@ -21,7 +21,8 @@
     "dist:all": "npm run dist:demo-server && npm run dist:cm && npm run dist:cm6 && npm run dist:pm && npm run dist:pm-versions && npm run dist:quill && npm run dist:monaco",
     "lint": "standard",
     "deploy": "fly deploy --ha=false",
-    "pm2": "cd demo-server && pm2-runtime start ./demo-server.js",
+    "pm2_alt": "cd demo-server && pm2-runtime start ./demo-server.js",
+    "pm2": "cd demo-server && npm start",
     "container:build": "docker build . -t yjs-demos",
     "container:run": "docker run -p 3000:3000 --name yjs-demos yjs-demos",
     "container:stop": "docker stop yjs-demos && docker remove yjs-demos"