Try something

apps/panoramablick-saalbach.at/nuxt.config.ts

@@ -30,4 +30,12 @@ export default defineNuxtConfig({
     provider: 'server',
     serverBundle: 'local'
   },
+  nitro: {
+    prerender: {
+      routes: ['/de/summer'],
+    },
+  },
+  routeRules: {
+    '/': { prerender: false },
+  },
 })

apps/panoramablick-saalbach.at/pages/index.vue

@@ -1,13 +0,0 @@
-<!-- This page just exists to ensure all pages are found during pre-rendered -->
-
-<template>
-  Hello
-<!--  <NuxtLink :to="buildPrefix(preferredLocale, preferredVariant)"></NuxtLink>-->
-</template>
-
-<script setup lang="ts">
-definePageMeta({layout: false}) // crashes otherwise if multiple languages/variants
-
-// const {buildPrefix} = useContentPrefix()
-// const {preferredLocale, preferredVariant} = useContentPreference()
-</script>

packages/layers/content/middleware/content-routing.global.ts

@@ -1,10 +1,6 @@
 export default defineNuxtRouteMiddleware((to, from) => {
   // important: routes do not exist in middleware, never (in)directly use e.g. useRoute
 
-  if (import.meta.prerender) {
-    return // it will interfere with pre-rendering otherwise
-  }
-
   const {getLocaleVariant, buildPrefix} = useContentPrefix()
   const localeVariant = getLocaleVariant(to.path)