fix(ui): component AddNewRelation saves relationTo as first collection instead of selected collection

docs/access-control/collections.mdx

@@ -339,8 +339,9 @@ export const CollectionWithVersionsAccess: CollectionConfig = {
 ```
 
 <Banner type="warning">
-  **Note:** Returning a [Query](../queries/overview) will apply the constraint to the
-  [`versions` collection](../versions/overview#database-impact), not the original Collection.
+  **Note:** Returning a [Query](../queries/overview) will apply the constraint
+  to the [`versions` collection](../versions/overview#database-impact), not the
+  original Collection.
 </Banner>
 
 The following arguments are provided to the `readVersions` function:

docs/access-control/globals.mdx

@@ -137,8 +137,9 @@ export const GlobalWithVersionsAccess: GlobalConfig = {
 ```
 
 <Banner type="warning">
-  **Note:** Returning a [Query](../queries/overview) will apply the constraint to the
-  [`versions` collection](../versions/overview#database-impact), not the original Global.
+  **Note:** Returning a [Query](../queries/overview) will apply the constraint
+  to the [`versions` collection](../versions/overview#database-impact), not the
+  original Global.
 </Banner>
 
 The following arguments are provided to the `readVersions` function:

packages/ui/src/elements/AddNewRelation/index.tsx

@@ -79,7 +79,7 @@ export const AddNewRelation: React.FC<Props> = ({
             ])
           } else {
             onChange({
-              relationTo: relatedCollections[0].slug,
+              relationTo: collectionConfig?.slug,
               value: doc.id,
             })
           }
@@ -88,7 +88,7 @@ export const AddNewRelation: React.FC<Props> = ({
         setSelectedCollection(undefined)
       }
     },
-    [collectionConfig, hasMany, onChange, value, relatedCollections],
+    [collectionConfig, hasMany, onChange, value],
   )
 
   const onPopupToggle = useCallback((state) => {

test/fields/collections/Relationship/e2e.spec.ts

@@ -98,6 +98,32 @@ describe('relationship', () => {
     await expect(page.locator('.payload-toast-container')).toContainText('successfully')
   })
 
+  test('should save correct relationTo when creating doc in second collection (bug #14728)', async () => {
+    await loadCreatePage()
+
+    await openCreateDocDrawer({ page, fieldSelector: '#field-relationship' })
+
+    // Select the SECOND collection (array-fields) instead of the first (text-fields)
+    await page
+      .locator('#field-relationship .relationship-add-new__relation-button--array-fields')
+      .click()
+
+    await page.locator('[id^=doc-drawer_array-fields_1_] #action-save').click()
+    await expect(page.locator('.payload-toast-container')).toContainText('successfully')
+    await page.locator('[id^=close-drawer__doc-drawer_array-fields_1_]').click()
+
+    const relationshipValue = page.locator('#field-relationship .relationship--single-value__text')
+    await expect(relationshipValue).toBeVisible()
+    await expect(async () => {
+      const valueText = await relationshipValue.textContent()
+      expect(valueText).not.toContain('Another text document')
+      expect(valueText).not.toContain('Untitled')
+    }).toPass()
+
+    await page.locator('#action-save').click()
+    await expect(page.locator('.payload-toast-container')).toContainText('successfully')
+  })
+
   test('should create nested inline relationships', async () => {
     await loadCreatePage()