diff --git a/src/WebformBuilder.js b/src/WebformBuilder.js
index 5319106c4b..6a280b9291 100644
--- a/src/WebformBuilder.js
+++ b/src/WebformBuilder.js
@@ -1243,6 +1243,12 @@ export default class WebformBuilder extends Component {
           parentComponent.tabs[tabIndex].splice(index, 1, newComp);
           newComp.checkValidity = () => true;
           newComp.build(defaultValueComponent.element);
+          if (this.preview && !this.preview.defaultChanged) {
+            const defaultValue = _.get(this.preview._data, this.editForm._data.key);
+            if (_.isObject(defaultValue) && !_.isArray(defaultValue)) {
+              this.editForm._data.defaultValue = defaultValue;
+            }
+          }
         }
       }
       else {
@@ -1256,6 +1262,7 @@ export default class WebformBuilder extends Component {
           dataPath = getStringFromComponentPath(path);
         }
 
+        this.preview.defaultChanged = true;
         _.set(this.preview._data, dataPath, changed.value);
         _.set(this.webform._data, dataPath, changed.value);
       }
diff --git a/src/components/selectboxes/SelectBoxes.js b/src/components/selectboxes/SelectBoxes.js
index 6919738b63..9dce6cb829 100644
--- a/src/components/selectboxes/SelectBoxes.js
+++ b/src/components/selectboxes/SelectBoxes.js
@@ -164,6 +164,14 @@ export default class SelectBoxesComponent extends RadioComponent {
       _.set(submission.metadata.selectData, this.path, selectData);
     }
 
+    // Ensure that for dataSrc == 'values' that there are not any other superfluous values.
+    if (this.component.dataSrc === 'values') {
+      for (const key in value) {
+        if (!this.component.values.find((val) => val.value === key)) {
+          delete value[key];
+        }
+      }
+    }
     return value;
   }