diff --git a/app/javascript/controllers/rule/conditions_controller.js b/app/javascript/controllers/rule/conditions_controller.js
index d0c12941..1a20d00d 100644
--- a/app/javascript/controllers/rule/conditions_controller.js
+++ b/app/javascript/controllers/rule/conditions_controller.js
@@ -13,7 +13,7 @@ export default class extends Controller {
 
   addSubCondition() {
     const html = this.subConditionTemplateTarget.innerHTML.replaceAll(
-      "IDX_PLACEHOLDER",
+      "IDX_CHILD_PLACEHOLDER",
       this.#uniqueKey(),
     );
 
@@ -110,6 +110,6 @@ export default class extends Controller {
   }
 
   #uniqueKey() {
-    return Math.random().toString(36).substring(2, 15);
+    return Date.now();
   }
 }
diff --git a/app/views/rule/conditions/_condition_group.html.erb b/app/views/rule/conditions/_condition_group.html.erb
index e04a09f7..77383833 100644
--- a/app/views/rule/conditions/_condition_group.html.erb
+++ b/app/views/rule/conditions/_condition_group.html.erb
@@ -28,13 +28,13 @@
 
   <%# Sub-condition template, used by Stimulus controller to add new sub-conditions dynamically %>
   <template data-rule--conditions-target="subConditionTemplate">
-    <%= form.fields_for :sub_conditions, Rule::Condition.new(parent: condition, condition_type: rule.condition_filters.first.key), child_index: "IDX_PLACEHOLDER" do |scf| %>
+    <%= form.fields_for :sub_conditions, Rule::Condition.new(parent: condition, condition_type: rule.condition_filters.first.key), child_index: "IDX_CHILD_PLACEHOLDER" do |scf| %>
       <%= render "rule/conditions/condition", form: scf, show_prefix: false %>
     <% end %>
   </template>
 
   <ul data-rule--conditions-target="subConditionsList" class="space-y-3">
-    <%= form.fields_for :sub_conditions do |scf| %>
+    <%= form.fields_for :sub_conditions, condition.sub_conditions.select(&:persisted?) do |scf| %>
       <%= render "rule/conditions/condition", form: scf, show_prefix: false %>
     <% end %>
   </ul>