diff --git a/src/components/renderer/form-nested-screen.vue b/src/components/renderer/form-nested-screen.vue
index 4c7ca872..fbe92a2d 100644
--- a/src/components/renderer/form-nested-screen.vue
+++ b/src/components/renderer/form-nested-screen.vue
@@ -72,6 +72,17 @@ export default {
     },
   },
   methods: {
+    isInScreenBuilder() {
+      let parent = this.$parent;
+      while (parent) {
+        const { _componentTag: tag, name } = parent.$options;
+        if (tag === 'vue-form-builder' || tag === 'VueFormBuilder' || name === 'VueFormBuilder') {
+          return true;
+        }
+        parent = parent.$parent;
+      }
+      return false;
+    },
     isSubmitButton(item) {
       return item.config && item.component === 'FormButton' && item.config.event === 'submit';
     },
@@ -130,7 +141,7 @@ export default {
             this.hideSubmitButtons(this.config);
             this.computed = response.data.computed;
             this.customCSS = response.data.custom_css;
-            this.watchers = response.data.watchers;
+            this.watchers = this.isInScreenBuilder() ? [] : response.data.watchers;
             this.screenTitle = response.data.title;
 
             if (this.$attrs['disabled']) {
diff --git a/src/components/vue-form-builder.vue b/src/components/vue-form-builder.vue
index 1f616fb1..b959d8ca 100644
--- a/src/components/vue-form-builder.vue
+++ b/src/components/vue-form-builder.vue
@@ -615,6 +615,7 @@ const defaultGroupOrder = {
 const DEFAULT_GROUP = "Advanced";
 
 export default {
+  name: 'VueFormBuilder',
   components: {
     TabsBar,
     draggable,
diff --git a/tests/unit/FormNestedScreen.spec.js b/tests/unit/FormNestedScreen.spec.js
new file mode 100644
index 00000000..cab3a9fb
--- /dev/null
+++ b/tests/unit/FormNestedScreen.spec.js
@@ -0,0 +1,173 @@
+const fs = require('fs');
+const path = require('path');
+const vm = require('vm');
+
+const componentPath = path.join(
+  process.cwd(),
+  'src/components/renderer/form-nested-screen.vue',
+);
+
+const source = fs.readFileSync(componentPath, 'utf8');
+
+function getComponentOptions() {
+  const scriptMatch = source.match(/<script>([\s\S]*?)<\/script>/);
+
+  if (!scriptMatch) {
+    throw new Error('Unable to find form-nested-screen.vue script block');
+  }
+
+  const executableScript = scriptMatch[1]
+    .replace(/^import .*$/gm, '')
+    .replace('export default', 'module.exports =');
+
+  const sandbox = {
+    module: { exports: {} },
+    exports: {},
+    window: {},
+    global: {},
+    VueFormRenderer: {},
+    Promise,
+    setTimeout,
+    clearTimeout,
+    console,
+  };
+
+  vm.runInNewContext(executableScript, sandbox, { filename: componentPath });
+
+  return sandbox.module.exports;
+}
+
+const FormNestedScreen = getComponentOptions();
+
+const makeContext = (parents) => {
+  let parent = null;
+
+  [...parents].reverse().forEach((options) => {
+    parent = { $options: options, $parent: parent };
+  });
+
+  return { $parent: parent };
+};
+
+describe('FormNestedScreen design mode watchers', () => {
+  test('detects vue-form-builder tag in parent chain', () => {
+    const context = makeContext([
+      { _componentTag: 'div' },
+      { _componentTag: 'vue-form-builder' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(true);
+  });
+
+  test('detects VueFormBuilder tag in parent chain', () => {
+    const context = makeContext([
+      { _componentTag: 'VueFormBuilder' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(true);
+  });
+
+  test('detects VueFormBuilder name in parent chain', () => {
+    const context = makeContext([
+      { _componentTag: 'div', name: 'VueFormBuilder' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(true);
+  });
+
+  test('returns false outside screen builder', () => {
+    const context = makeContext([
+      { _componentTag: 'screen-renderer' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(false);
+  });
+
+  test('detects screen builder through deeply nested screens', () => {
+    const context = makeContext([
+      { _componentTag: 'vue-form-renderer' },
+      { _componentTag: 'FormNestedScreen' },
+      { _componentTag: 'vue-form-renderer' },
+      { _componentTag: 'FormNestedScreen' },
+      { _componentTag: 'vue-form-builder', name: 'VueFormBuilder' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(true);
+  });
+
+  test('does not treat preview renderer as screen builder', () => {
+    const context = makeContext([
+      { _componentTag: 'vue-form-renderer' },
+      { _componentTag: 'b-col' },
+      { _componentTag: 'b-row' },
+    ]);
+
+    expect(FormNestedScreen.methods.isInScreenBuilder.call(context)).toBe(false);
+  });
+
+  test('does not load watchers when rendered inside screen builder', async () => {
+    const watchers = [{ uid: 'watcher-1', run_onload: true }];
+    const context = Object.assign(
+      makeContext([{ _componentTag: 'vue-form-builder' }]),
+      FormNestedScreen.methods,
+      {
+        config: [],
+        computed: [],
+        customCSS: null,
+        watchers: [],
+        screenTitle: null,
+        ancestorScreens: [],
+        $attrs: {},
+        $root: { $emit: jest.fn() },
+        $dataProvider: {
+          getScreen: jest.fn().mockResolvedValue({
+            data: {
+              config: [{ name: 'Page 1', items: [] }],
+              computed: [],
+              custom_css: '',
+              watchers,
+              title: 'Nested Screen',
+            },
+          }),
+        },
+      },
+    );
+
+    await FormNestedScreen.methods.loadScreen.call(context, 1);
+
+    expect(context.watchers).toEqual([]);
+  });
+
+  test('loads watchers in preview/runtime context', async () => {
+    const watchers = [{ uid: 'watcher-1', run_onload: true }];
+    const context = Object.assign(
+      makeContext([{ _componentTag: 'screen-renderer' }]),
+      FormNestedScreen.methods,
+      {
+        config: [],
+        computed: [],
+        customCSS: null,
+        watchers: [],
+        screenTitle: null,
+        ancestorScreens: [],
+        $attrs: {},
+        $root: { $emit: jest.fn() },
+        $dataProvider: {
+          getScreen: jest.fn().mockResolvedValue({
+            data: {
+              config: [{ name: 'Page 1', items: [] }],
+              computed: [],
+              custom_css: '',
+              watchers,
+              title: 'Nested Screen',
+            },
+          }),
+        },
+      },
+    );
+
+    await FormNestedScreen.methods.loadScreen.call(context, 1);
+
+    expect(context.watchers).toEqual(watchers);
+  });
+});