diff --git a/app/Controllers/Jobs.php b/app/Controllers/Jobs.php
index d5d15ab7a..5029635ed 100644
--- a/app/Controllers/Jobs.php
+++ b/app/Controllers/Jobs.php
@@ -98,14 +98,15 @@ class Jobs extends Secure_Controller
             }
         }
 
-        $success = true;
+        foreach ($arraySave as $throttleData) {
+            if (!ctype_digit((string)$throttleData['max_count']) || !in_array($throttleData['period'], $allowedPeriods, true)) {
+                $this->db->transRollback();
+
+                return $this->response->setJSON(['success' => false, 'message' => lang('Jobs.saved_unsuccessfully')]);
+            }
+        }
 
         foreach ($arraySave as $throttleId => $throttleData) {
-            if (!ctype_digit((string)$throttleData['max_count']) || !in_array($throttleData['period'], $allowedPeriods, true)) {
-                $success = false;
-                continue;
-            }
-
             $savedThrottleId = $this->jobThrottle->saveValue($throttleData, $throttleId);
             $notToDelete[] = (string)$savedThrottleId;
         }
@@ -121,7 +122,7 @@ class Jobs extends Secure_Controller
 
         $this->db->transComplete();
 
-        $success = $success && $this->db->transStatus();
+        $success = $this->db->transStatus();
 
         return $this->response->setJSON(['success' => $success, 'message' => lang('Jobs.saved_' . ($success ? '' : 'un') . 'successfully')]);
     }
diff --git a/tests/Controllers/JobsControllerTest.php b/tests/Controllers/JobsControllerTest.php
index 6ce929ebb..c49ce2eda 100644
--- a/tests/Controllers/JobsControllerTest.php
+++ b/tests/Controllers/JobsControllerTest.php
@@ -135,6 +135,26 @@ class JobsControllerTest extends CIUnitTestCase
         $this->assertFalse($result['success']);
     }
 
+    public function testPostSaveThrottlesLeavesExistingThrottlesUnchangedWhenPayloadInvalid(): void
+    {
+        $this->loginAsAdmin();
+        $this->jobThrottle->saveValue(['max_count' => 5, 'period' => 'minute'], 1);
+        $this->jobThrottle->saveValue(['max_count' => 20, 'period' => 'day'], 2);
+
+        // Throttle 2 is invalid and throttle 1 is omitted; neither should be touched.
+        $response = $this->post('/jobs/saveThrottles', [
+            'throttle_count_2'  => 15,
+            'throttle_period_2' => 'fortnight',
+        ]);
+
+        $response->assertStatus(200);
+        $result = json_decode($response->getJSON(), true);
+        $this->assertFalse($result['success']);
+
+        $this->seeInDatabase('job_throttles', ['throttle_id' => 1, 'max_count' => 5, 'period' => 'minute', 'deleted' => 0]);
+        $this->seeInDatabase('job_throttles', ['throttle_id' => 2, 'max_count' => 20, 'period' => 'day', 'deleted' => 0]);
+    }
+
     public function testGetThrottlesRendersPartial(): void
     {
         $this->loginAsAdmin();