diff --git a/cura/BuildVolume.py b/cura/BuildVolume.py
index 4f531a0871..caa83001c0 100755
--- a/cura/BuildVolume.py
+++ b/cura/BuildVolume.py
@@ -110,7 +110,7 @@ class BuildVolume(SceneNode):
 
     def _onChangeTimerFinished(self):
         root = Application.getInstance().getController().getScene().getRoot()
-        new_scene_objects = set(node for node in BreadthFirstIterator(root) if node.getMeshData() and type(node) is SceneNode)
+        new_scene_objects = set(node for node in BreadthFirstIterator(root) if node.callDecoration("isSliceable"))
         if new_scene_objects != self._scene_objects:
             for node in new_scene_objects - self._scene_objects: #Nodes that were added to the scene.
                 self._onNodeDecoratorChanged(node)
diff --git a/cura/PrintInformation.py b/cura/PrintInformation.py
index 15cae19ec9..0369f536fa 100644
--- a/cura/PrintInformation.py
+++ b/cura/PrintInformation.py
@@ -75,6 +75,8 @@ class PrintInformation(QObject):
         Application.getInstance().getMachineManager().activeMaterialChanged.connect(self._onActiveMaterialChanged)
         self._onActiveMaterialChanged()
 
+        self._material_amounts = []
+
     currentPrintTimeChanged = pyqtSignal()
 
     preSlicedChanged = pyqtSignal()
diff --git a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
index 323f51dafe..8c722b0b01 100644
--- a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
+++ b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
@@ -852,7 +852,6 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
         url = QUrl("http://" + self._address + self._api_prefix + "auth/request")
         request = QNetworkRequest(url)
         request.setHeader(QNetworkRequest.ContentTypeHeader, "application/json")
-        self.setAuthenticationState(AuthState.AuthenticationRequested)
         self._manager.post(request, json.dumps({"application": "Cura-" + Application.getInstance().getVersion(), "user": self._getUserName()}).encode())
 
     ##  Send all material profiles to the printer.
@@ -1033,7 +1032,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
             if "/auth/request" in reply_url:
                 # We got a response to requesting authentication.
                 data = json.loads(bytes(reply.readAll()).decode("utf-8"))
-
+                self.setAuthenticationState(AuthState.AuthenticationRequested)
                 global_container_stack = Application.getInstance().getGlobalContainerStack()
                 if global_container_stack:  # Remove any old data.
                     Logger.log("d", "Removing old network authentication data as a new one was requested.")