diff --git a/src/slic3r/GUI/NotificationManager.cpp b/src/slic3r/GUI/NotificationManager.cpp
index a984b6ba7..0af8e32f5 100644
--- a/src/slic3r/GUI/NotificationManager.cpp
+++ b/src/slic3r/GUI/NotificationManager.cpp
@@ -2068,9 +2068,11 @@ bool NotificationManager::update_notifications(GLCanvas3D& canvas)
 		if ((*it).remaining_time > 0)
 			(*it).remaining_time -= time_since_render;
 		if ((*it).remaining_time <= 0) {
-			if ((*it).condition_callback()) { // push notification, erase it from waiting list (frame is scheduled by push)
+			if ((*it).notification && (*it).condition_callback()) { // push notification, erase it from waiting list (frame is scheduled by push)
 				(*it).notification->reset_timer();
-				if (push_notification_data(std::move((*it).notification), 0)) {
+				// if activate_existing returns false, we expect push to return true.
+				if(!this->activate_existing((*it).notification.get()) || (*it).delay_interval == 0) {
+					push_notification_data(std::move((*it).notification), 0);
 					it = m_waiting_notifications.erase(it);
 					continue;
 				}
@@ -2107,11 +2109,13 @@ bool NotificationManager::activate_existing(const NotificationManager::PopNotifi
 	const std::string &new_text = notification->get_data().text1;
 	for (auto it = m_pop_notifications.begin(); it != m_pop_notifications.end(); ++it) {
 		if ((*it)->get_type() == new_type && !(*it)->is_finished()) {
+			// multiple of one type allowed, but must have different text
 			if (std::find(m_multiple_types.begin(), m_multiple_types.end(), new_type) != m_multiple_types.end()) {
 				// If found same type and same text, return true - update will be performed on the old notif
 				if ((*it)->compare_text(new_text) == false) {
 					continue;
 				}
+			// multiple of one type allowed, but must have different text nad ObjectID 
 			} else if (new_type == NotificationType::SlicingWarning) {
 				auto w1 = dynamic_cast<const ObjectIDNotification*>(notification);
 				auto w2 = dynamic_cast<const ObjectIDNotification*>(it->get());
diff --git a/src/slic3r/GUI/NotificationManager.hpp b/src/slic3r/GUI/NotificationManager.hpp
index 655b17e63..6c50f6407 100644
--- a/src/slic3r/GUI/NotificationManager.hpp
+++ b/src/slic3r/GUI/NotificationManager.hpp
@@ -706,6 +706,7 @@ private:
 	// Otherwise another delay interval waiting. Timestamp is 0. 
 	// Note that notification object is constructed when being added to the waiting list, but there are no updates called on it and its timer is reset at regular push.
 	// Also note that no control of same notification is done during push_delayed_notification_data but if waiting notif fails to push, it continues waiting.
+	// If delay_interval is 0, notification is pushed only after initial_delay no matter the result. 
 	void push_delayed_notification_data(std::unique_ptr<NotificationManager::PopNotification> notification, std::function<bool(void)> condition_callback, int64_t initial_delay, int64_t delay_interval);
 	//finds older notification of same type and moves it to the end of queue. returns true if found
 	bool activate_existing(const NotificationManager::PopNotification* notification);
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index ec09ac1ad..57c8a2328 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -4030,7 +4030,7 @@ void Plater::priv::on_export_began(wxCommandEvent& evt)
 {
 	if (show_warning_dialog)
 		warnings_dialog();  
-    notification_manager->push_delayed_notification(NotificationType::ExportOngoing, [](){return true;}, 1000, 1000);
+    notification_manager->push_delayed_notification(NotificationType::ExportOngoing, [](){return true;}, 1000, 0);
 }
 void Plater::priv::on_slicing_began()
 {