diff --git a/lib/NGCP/Panel/Controller/API/SoundFiles.pm b/lib/NGCP/Panel/Controller/API/SoundFiles.pm
index 79a01d0d7f..be6ba435ce 100644
--- a/lib/NGCP/Panel/Controller/API/SoundFiles.pm
+++ b/lib/NGCP/Panel/Controller/API/SoundFiles.pm
@@ -53,6 +53,7 @@ sub relation{
 
 __PACKAGE__->set_config({
     allowed_roles => [qw/admin reseller subscriberadmin/],
+    set_transaction_isolation => 'READ COMMITTED',
 });
 
 sub auto :Private {
@@ -108,6 +109,7 @@ sub GET :Allow {
 sub POST :Allow {
     my ($self, $c) = @_;
 
+    $c->model('DB')->set_transaction_isolation('READ COMMITTED');
     my $guard = $c->model('DB')->txn_scope_guard;
     {
         my ($recording, $resource);
diff --git a/lib/NGCP/Panel/Controller/API/SoundFilesItem.pm b/lib/NGCP/Panel/Controller/API/SoundFilesItem.pm
index d530fe3d3f..70b1b581ac 100644
--- a/lib/NGCP/Panel/Controller/API/SoundFilesItem.pm
+++ b/lib/NGCP/Panel/Controller/API/SoundFilesItem.pm
@@ -31,6 +31,7 @@ sub relation{
 
 __PACKAGE__->set_config({
     allowed_roles => [qw/admin reseller subscriberadmin/],
+    set_transaction_isolation => 'READ COMMITTED',
 });
 
 sub GET :Allow {
@@ -57,6 +58,8 @@ sub GET :Allow {
 
 sub PUT :Allow {
     my ($self, $c, $id) = @_;
+
+    $c->model('DB')->set_transaction_isolation('READ COMMITTED');
     my $guard = $c->model('DB')->txn_scope_guard;
     {
         my $preference = $self->require_preference($c);
@@ -87,6 +90,8 @@ sub PUT :Allow {
 
 sub PATCH :Allow {
     my ($self, $c, $id) = @_;
+
+    $c->model('DB')->set_transaction_isolation('READ COMMITTED');
     my $guard = $c->model('DB')->txn_scope_guard;
     {
         my $preference = $self->require_preference($c);
@@ -119,6 +124,7 @@ sub PATCH :Allow {
 sub DELETE :Allow {
     my ($self, $c, $id) = @_;
 
+    $c->model('DB')->set_transaction_isolation('READ COMMITTED');
     my $guard = $c->model('DB')->txn_scope_guard;
     {
         my $item = $self->item_by_id($c, $id);
diff --git a/lib/NGCP/Panel/Controller/API/SoundSets.pm b/lib/NGCP/Panel/Controller/API/SoundSets.pm
index b109027ebf..3a2de92243 100644
--- a/lib/NGCP/Panel/Controller/API/SoundSets.pm
+++ b/lib/NGCP/Panel/Controller/API/SoundSets.pm
@@ -8,6 +8,7 @@ use parent qw/NGCP::Panel::Role::Entities NGCP::Panel::Role::API::SoundSets/;
 
 __PACKAGE__->set_config({
     allowed_roles => [qw/admin reseller subscriberadmin/],
+    set_transaction_isolation => 'READ COMMITTED',
 });
 
 sub allowed_methods{
diff --git a/lib/NGCP/Panel/Controller/API/SoundSetsItem.pm b/lib/NGCP/Panel/Controller/API/SoundSetsItem.pm
index 61293e6ad4..b363383afb 100644
--- a/lib/NGCP/Panel/Controller/API/SoundSetsItem.pm
+++ b/lib/NGCP/Panel/Controller/API/SoundSetsItem.pm
@@ -11,7 +11,8 @@ __PACKAGE__->set_config({
     allowed_roles => {
         Default => [qw/admin reseller subscriberadmin/],
         Journal => [qw/admin reseller subscriberadmin/],
-    }
+    },
+    set_transaction_isolation => 'READ COMMITTED',
 });
 
 sub allowed_methods{
diff --git a/lib/NGCP/Panel/Controller/Sound.pm b/lib/NGCP/Panel/Controller/Sound.pm
index c5fcd877a9..fd5570c5b9 100644
--- a/lib/NGCP/Panel/Controller/Sound.pm
+++ b/lib/NGCP/Panel/Controller/Sound.pm
@@ -271,6 +271,7 @@ sub edit :Chained('base') :PathPart('edit') {
                     die "an attempt to edit a sound set that does not belong to the subscriberadmin";
             }
 
+            $c->model('DB')->set_transaction_isolation('READ COMMITTED');
             $c->model('DB')->txn_do(sub {
                 if ($c->stash->{set_result}->expose_to_customer == 1 &&
                     $form->values->{expose_to_customer} == 0) {
@@ -298,7 +299,7 @@ sub edit :Chained('base') :PathPart('edit') {
                 # invalidate cache of this sound set if parent is changed
                 if ((!$old_parent_id && $parent_id) ||
                      ($old_parent_id && !$parent_id) ||
-                      $old_parent_id != $parent_id) {
+                     ($old_parent_id && $parent_id && $old_parent_id != $parent_id)) {
                     NGCP::Panel::Utils::Sems::clear_audio_cache($c, $own_id);
                 }
 
@@ -336,6 +337,7 @@ sub delete_sound :Chained('base') :PathPart('delete') {
     try {
 
         my $schema = $c->model('DB');
+        $schema->set_transaction_isolation('READ COMMITTED');
         $schema->txn_do(sub {
 
             my $own_id = $c->stash->{set_result}->id;
@@ -453,6 +455,7 @@ sub create :Chained('sets_list') :PathPart('create') :Args() {
             delete $form->values->{parent};
 
             my $schema = $c->model('DB');
+            $schema->set_transaction_isolation('READ COMMITTED');
             $schema->txn_do(sub {
                 # if a new contract default is set, clear old ones first
                 if($form->values->{contract_id} && $form->values->{contract_default} == 1) {
@@ -589,7 +592,6 @@ sub handles_edit :Chained('handles_base') :PathPart('edit') {
 
     if($posted && $form->validated) {
         # only if the form is validated and a POST is issued, insert the sound file in the db
-        $file_result->insert();
         if (defined $upload) {
             my $soundfile = eval { $upload->slurp };
             my $filename = eval { $upload->filename };
@@ -619,12 +621,17 @@ sub handles_edit :Chained('handles_base') :PathPart('edit') {
             }
 
             try {
-                $file_result->update({
-                    loopplay => $form->values->{loopplay},
-                    use_parent => $form->values->{use_parent},
-                    filename => $filename,
-                    data => $soundfile,
-                    codec => $target_codec,
+                my $schema = $c->model('DB');
+                $schema->set_transaction_isolation('READ COMMITTED');
+                $schema->txn_do(sub {
+                    $file_result->insert();
+                    $file_result->update({
+                        loopplay => $form->values->{loopplay},
+                        use_parent => $form->values->{use_parent},
+                        filename => $filename,
+                        data => $soundfile,
+                        codec => $target_codec,
+                    });
                 });
                 NGCP::Panel::Utils::Message::info(
                     c    => $c,
@@ -639,9 +646,14 @@ sub handles_edit :Chained('handles_base') :PathPart('edit') {
             }
         } else {
             try {
-                $file_result->update({
-                    loopplay => $form->values->{loopplay},
-                    use_parent => $form->values->{use_parent},
+                my $schema = $c->model('DB');
+                $schema->set_transaction_isolation('READ COMMITTED');
+                $schema->txn_do(sub {
+                    $file_result->insert();
+                    $file_result->update({
+                        loopplay => $form->values->{loopplay},
+                        use_parent => $form->values->{use_parent},
+                    });
                 });
                 NGCP::Panel::Utils::Message::info(
                     c    => $c,
@@ -683,7 +695,11 @@ sub handles_delete :Chained('handles_base') :PathPart('delete') {
     $self->check_subadmin_handle_edit_access($c, $c->stash->{file_result});
 
     try {
-        $c->stash->{file_result}->delete;
+        my $schema = $c->model('DB');
+        $schema->set_transaction_isolation('READ COMMITTED');
+        $schema->txn_do(sub {
+            $c->stash->{file_result}->delete;
+        });
         NGCP::Panel::Utils::Message::info(
             c    => $c,
             data => { $c->stash->{file_result}->get_inflated_columns },
diff --git a/lib/NGCP/Panel/Role/API/SoundSets.pm b/lib/NGCP/Panel/Role/API/SoundSets.pm
index b4c4a658b8..b2cbae6ad5 100644
--- a/lib/NGCP/Panel/Role/API/SoundSets.pm
+++ b/lib/NGCP/Panel/Role/API/SoundSets.pm
@@ -188,7 +188,7 @@ sub update_item_model {
     my $parent_id = $resource->{parent_id};
     if ((!$old_parent_id && $parent_id) ||
          ($old_parent_id && !$parent_id) ||
-          $old_parent_id != $parent_id) {
+         ($old_parent_id && $parent_id && $old_parent_id != $parent_id)) {
         NGCP::Panel::Utils::Sems::clear_audio_cache($c, $item->id);
     }