correct fix

src/client/app/router.ts

@@ -180,7 +180,7 @@ export function createRouter(
               : link.href,
             link.baseURI
           )
-          const currentUrl = window.location
+          const currentUrl = new URL(window.location.href) // copy to keep old data
           // only intercept inbound html links
           if (
             !e.ctrlKey &&
@@ -211,7 +211,12 @@ export function createRouter(
                 window.scrollTo(0, 0)
               }
             } else {
-              go(href)
+              go(href).then(() => {
+                // do after the route is changed so location.hash in theme code is the new hash
+                if (hash !== currentUrl.hash) {
+                  window.dispatchEvent(new Event('hashchange'))
+                }
+              })
             }
           }
         }

src/client/theme-default/composables/langs.ts

@@ -1,4 +1,4 @@
-import { computed, watch } from 'vue'
+import { computed } from 'vue'
 import { ensureStartingSlash } from '../support/utils'
 import { useData } from './data'
 import { hashRef } from './hash'
@@ -15,10 +15,6 @@ export function useLangs({
       (localeIndex.value === 'root' ? '/' : `/${localeIndex.value}/`)
   }))
 
-  watch(page, () => {
-    hashRef.value = location.hash ? location.hash : ''
-  })
-
   const localeLinks = computed(() =>
     Object.entries(site.value.locales).flatMap(([key, value]) =>
       removeCurrent && currentLang.value.label === value.label