diff --git a/backend/app/migrator/native.go b/backend/app/migrator/native.go
index cf52c528..bf60d834 100644
--- a/backend/app/migrator/native.go
+++ b/backend/app/migrator/native.go
@@ -109,7 +109,7 @@ func (n *Native) Import(reader io.Reader, siteID string) (size int, err error) {
 	if n.Concurrent > 0 {
 		concurrent = n.Concurrent
 	}
-	grp := syncs.NewSizedGroup(concurrent)
+	grp := syncs.NewErrSizedGroup(concurrent, syncs.Preemptive())
 
 	for {
 		comment := store.Comment{}
@@ -127,21 +127,22 @@ func (n *Native) Import(reader io.Reader, siteID string) (size int, err error) {
 		}
 
 		// write comments in parallel
-		grp.Go(func() {
+		grp.Go(func() error {
 			if _, e := n.DataStore.Create(comment); e != nil {
 				atomic.AddInt64(&failed, 1)
 				log.Printf("[WARN] can't write %+v to store, %s", comment, e)
-				return
+				return nil
 			}
 			n := atomic.AddInt64(&comments, 1)
 			if n%1000 == 0 {
 				log.Printf("[DEBUG] imported %d comments", n)
 			}
+			return nil
 		})
 
 	}
 
-	grp.Wait()
+	_ = grp.Wait()
 
 	if failed > 0 {
 		return int(comments), errors.Errorf("failed to save %d comments", failed)
diff --git a/backend/app/rest/api/admin_test.go b/backend/app/rest/api/admin_test.go
index c0684ccc..d4848ab8 100644
--- a/backend/app/rest/api/admin_test.go
+++ b/backend/app/rest/api/admin_test.go
@@ -75,7 +75,7 @@ func TestAdmin_Delete(t *testing.T) {
 	assert.Equal(t, "", cr.Text)
 	assert.True(t, cr.Deleted)
 
-	time.Sleep(100 * time.Millisecond)
+	time.Sleep(250 * time.Millisecond)
 	// check last comments updated
 	res, code = get(t, ts.URL+"/api/v1/last/2?site=radio-t")
 	assert.Equal(t, 200, code)
diff --git a/backend/app/store/service/service_test.go b/backend/app/store/service/service_test.go
index 82fd5653..99babee2 100644
--- a/backend/app/store/service/service_test.go
+++ b/backend/app/store/service/service_test.go
@@ -145,6 +145,8 @@ func TestService_SetTitle(t *testing.T) {
 	t.Logf("%+v", res)
 	assert.Equal(t, "", res.PostTitle)
 
+	b.TitleExtractor.cache.Purge()
+
 	atomic.StoreInt32(&titleEnable, 1)
 	c, err := b.SetTitle(store.Locator{URL: tss.URL + "/post1", SiteID: "radio-t"}, id)
 	require.NoError(t, err)