diff --git a/plugin-designs/research-map-plus-grid/research-map-plus-grid.vue b/plugin-designs/research-map-plus-grid/research-map-plus-grid.vue
index d3a13ba7e..26d39dcfc 100644
--- a/plugin-designs/research-map-plus-grid/research-map-plus-grid.vue
+++ b/plugin-designs/research-map-plus-grid/research-map-plus-grid.vue
@@ -423,6 +423,13 @@ function pushToChildren() {
     let cfg = {}
     try { cfg = JSON.parse(map.getAttribute('profile-config') || '{}') } catch (_) { cfg = {} }
     cfg.externalFilters = { region: linked.region.value, religion: linked.religion, language: linked.language.label, fitSlugs: gridSlugs.value }
+    // ★ AND THE LOCALE. This rewrote the FILTERS and nothing else, so a live language switch moved
+    // the composite's own chrome and never reached the panes: the outer element got the new
+    // profile-config, this re-parsed the child's EXISTING attribute, and the boot `lang` survived
+    // every push. MEASURED: the map stayed English on a live en->ar switch while the composite
+    // around it changed. The leaf's own chain is fully reactive and was never at fault — it is
+    // reactive to its own prop, and its prop was frozen.
+    if (hostLang.value) cfg.lang = hostLang.value
     map.setAttribute('profile-config', JSON.stringify(cfg))
   }
   const grid = rootEl.querySelector('people-groups-grid')
@@ -433,8 +440,21 @@ function pushToChildren() {
     // so a stable ISO code matches in every locale while a display name only matches in the one it
     // was fetched in.
     grid.setAttribute('primary-language', gridLanguage())
+    // The grid's three linked facets travel as their own attributes, but its LANGUAGE does not —
+    // it reads that from profile-config, which this composite set only when a host list was
+    // supplied, and never again. Same frozen-prop defect as the map above, one channel over.
+    if (hostLang.value) {
+      let gcfg = {}
+      try { gcfg = JSON.parse(grid.getAttribute('profile-config') || '{}') } catch (_) { gcfg = {} }
+      if (gcfg.lang !== hostLang.value) {
+        gcfg.lang = hostLang.value
+        grid.setAttribute('profile-config', JSON.stringify(gcfg))
+      }
+    }
   }
 }
+// A locale change has to reach the panes too; `linked` and `gridSlugs` only cover filter state.
+watch(hostLang, pushToChildren)
 watch(linked, pushToChildren, { deep: true })
 // The slug set changes without any facet changing (a search term, a cleared filter), so it needs
 // its own trigger — `linked` alone would leave the camera behind.