Well thats stupid it has to be like this

astro.config.mjs

@@ -5,8 +5,6 @@ import node from '@astrojs/node';
 export default defineConfig({
   output: 'server',
   adapter: node({
-    host: '0.0.0.0',
-    port: 4321, // default port for Astro SSR
     mode: 'standalone', // bundles dependencies with output
   }),
   integrations: [react()],

package.json

@@ -7,7 +7,7 @@
     "build": "astro build",
     "preview": "astro preview",
     "astro": "astro",
-    "start": "bun ./dist/server/entry.mjs"
+    "start": "HOST=0.0.0.0 PORT=4321 bun ./dist/server/entry.mjs"
   },
   "dependencies": {
     "@astrojs/node": "^9.3.0",