FactComboBox: keep index onModelChanged

src/FactSystem/FactControls/FactComboBox.qml

@@ -14,6 +14,17 @@ QGCComboBox {
 
     currentIndex: fact ? (indexModel ? fact.value : fact.enumIndex) : 0
 
+    onModelChanged: {
+        // When the model changes, the index gets reset to 0, so make sure to
+        // restore it correctly.
+        // Since enumIndex could trigger a model change, we use callLater() to
+        // avoid an event binding loop (the 2. call will for certain not trigger
+        // another model change)
+        Qt.callLater(function() {
+            currentIndex = fact ? (indexModel ? fact.value : fact.enumIndex) : 0
+        })
+    }
+
     onActivated: {
         if (indexModel) {
             fact.value = index