diff --git a/library/components/legends/SemanticTreeLegend.vue b/library/components/legends/SemanticTreeLegend.vue
index 174e2d0d1..6f82578f9 100644
--- a/library/components/legends/SemanticTreeLegend.vue
+++ b/library/components/legends/SemanticTreeLegend.vue
@@ -288,6 +288,27 @@ watch(() => props.open, (v) => {
 })
 
 watch(() => safeNodes.value, () => {
+  // ★ A DATA REFRESH IS NOT A DESELECTION (rega, WAGF Regions on Simple Research, 2026-09-28). The
+  // polygon highlight landed 51-85 ms after the click and was wiped 433-667 ms later, leaving no row
+  // marked and every region at full colour — which reads exactly like the Driver's "the legend isn't
+  // connecting with the map", and is worse, because it connected and then undid itself.
+  //
+  // This watcher fires on the IDENTITY of the nodes array, and every tree here is a computed that
+  // returns a NEW array on each evaluation. So any late async that touches a dependency — pins still
+  // arriving, a lazily loaded layer, a refresh — rebuilt the array with IDENTICAL CONTENT and this
+  // reset cancelled the user's selection. The reset itself is right for genuinely new data; what was
+  // wrong is that it could not tell one case from the other.
+  //
+  // So ask whether the selected row still EXISTS. If it does, re-point at the new object and leave the
+  // tab and the expansion alone: nothing about the reader's state has become invalid. If it is gone,
+  // the reset below is correct and the deselect is honest.
+  const keepId = selectedNode.value?.id || null
+  if (keepId) {
+    const survivor = findNodeById(safeNodes.value, keepId)
+    // Re-pointed, not kept: the old object belongs to the discarded array, and holding it would make
+    // the highlight compare against a node the tree no longer contains.
+    if (survivor) { selectedNode.value = survivor; return }
+  }
   // Falls back to defaultTab, not a hardcoded 0 — otherwise a profile that opens on
   // a deeper generation silently reverts to the top the first time its nodes change.
   // ⚠ AND THE STORE ONLY COUNTS ONCE IT HAS BEEN TOUCHED. This read `instance?.activeTab.value`