diff --git a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
index fc3198a736..07c66e359a 100644
--- a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
+++ b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/DefaultTbAlarmService.java
@@ -216,7 +216,7 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
     }
 
     @Override
-    public void unassignUserAlarms(TenantId tenantId, User user, long unassignTs) throws ThingsboardException {
+    public void unassignUserAlarms(TenantId tenantId, User user, long unassignTs) {
         AlarmQueryV2 alarmQuery = AlarmQueryV2.builder().assigneeId(user.getId()).pageLink(new TimePageLink(Integer.MAX_VALUE)).build();
         try {
             List<AlarmInfo> alarms = alarmService.findAlarmsV2(tenantId, alarmQuery).get(30, TimeUnit.SECONDS).getData();
@@ -240,8 +240,6 @@ public class DefaultTbAlarmService extends AbstractTbEntityService implements Tb
                         log.error("Failed to save alarm comment", e);
                     }
                     notificationEntityService.notifyCreateOrUpdateAlarm(result.getAlarm(), ActionType.ALARM_UNASSIGNED, user);
-                } else {
-                    throw new ThingsboardException("Alarm was already unassigned!", ThingsboardErrorCode.BAD_REQUEST_PARAMS);
                 }
             }
 
diff --git a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/TbAlarmService.java b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/TbAlarmService.java
index ed4af5d1bd..24af185539 100644
--- a/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/TbAlarmService.java
+++ b/application/src/main/java/org/thingsboard/server/service/entitiy/alarm/TbAlarmService.java
@@ -38,7 +38,7 @@ public interface TbAlarmService {
 
     AlarmInfo unassign(Alarm alarm, long unassignTs, User user) throws ThingsboardException;
 
-    void unassignUserAlarms(TenantId tenantId, User user, long unassignTs) throws ThingsboardException;
+    void unassignUserAlarms(TenantId tenantId, User user, long unassignTs);
 
     Boolean delete(Alarm alarm, User user);
 }
diff --git a/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java b/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
index c2e34c5d2e..8f28ca0110 100644
--- a/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
+++ b/application/src/test/java/org/thingsboard/server/controller/AlarmControllerTest.java
@@ -557,25 +557,23 @@ public class AlarmControllerTest extends AbstractControllerTest {
 
         Mockito.reset(tbClusterService, auditLogService);
         long beforeAssignmentTs = System.currentTimeMillis();
-        Thread.sleep(2);
 
         doPost("/api/alarm/" + alarm.getId() + "/assign/" + savedUser.getId().getId()).andExpect(status().isOk());
         AlarmInfo foundAlarm = doGet("/api/alarm/info/" + alarm.getId(), AlarmInfo.class);
         Assert.assertNotNull(foundAlarm);
         Assert.assertEquals(savedUser.getId(), foundAlarm.getAssigneeId());
-        Assert.assertTrue(foundAlarm.getAssignTs() > beforeAssignmentTs);
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
 
         beforeAssignmentTs = System.currentTimeMillis();
 
         Mockito.reset(tbClusterService, auditLogService);
 
         doDelete("/api/user/" + savedUser.getId().getId()).andExpect(status().isOk());
-        Thread.sleep(2);
 
         foundAlarm = doGet("/api/alarm/info/" + alarm.getId(), AlarmInfo.class);
         Assert.assertNotNull(foundAlarm);
         Assert.assertNull(foundAlarm.getAssigneeId());
-        Assert.assertTrue(foundAlarm.getAssignTs() > beforeAssignmentTs);
+        Assert.assertTrue(foundAlarm.getAssignTs() >= beforeAssignmentTs);
     }
 
     @Test