Add subkey

Closes #3518099

modules/ui_patterns_ui/src/Element/UiPComponentFormDisplaysForm.php

@@ -108,7 +108,7 @@ class UiPComponentFormDisplaysForm extends ComponentForm {
       ],
     ];
     if ($display_id === '_component_form') {
-      $element["display"]['value'] = [
+      $element["display"]['value_' . $display_id] = [
         '#type' => 'component_form',
         '#allow_override' => TRUE,
         '#component_id' => $component_id,
@@ -127,7 +127,7 @@ class UiPComponentFormDisplaysForm extends ComponentForm {
       ];
     }
     elseif ($display_id) {
-      $element["display"]['value'] = [
+      $element["display"]['value_' . $display_id] = [
         '#type' => 'uip_display_form',
         '#display_id' => $display_id,
         '#component_id' => $component_id,
@@ -185,8 +185,9 @@ class UiPComponentFormDisplaysForm extends ComponentForm {
    * {@inheritdoc}
    */
   public static function elementValidate(array &$element, FormStateInterface $form_state): void {
-    if (isset($element['display']['value']['#value'])) {
-      $element['#value'] = $element['display']['value']['#value'];
+    $display_id = $element['display']['display_id']['#value'];
+    if (isset($element['display']['value_' . $display_id]['#value'])) {
+      $element['#value'] = $element['display']['value_' . $display_id]['#value'];
 
       if (isset($element['display']['display_id'])
         && $element['display']['display_id']['#value'] !== '_component_form') {