diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index 02c5c04203..756dae2704 100755
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -1041,10 +1041,12 @@ class CuraApplication(QtApplication):
 
         nodes = []
         for node in DepthFirstIterator(self.getController().getScene().getRoot()):
-            if type(node) not in {SceneNode, CuraSceneNode}:
+            if not isinstance(node, SceneNode):
                 continue
             if (not node.getMeshData() and not node.callDecoration("getLayerData")) and not node.callDecoration("isGroup"):
                 continue  # Node that doesnt have a mesh and is not a group.
+            if not node.isSelectable():
+                continue  # Only remove nodes that are selectable.
             if node.getParent() and node.getParent().callDecoration("isGroup"):
                 continue  # Grouped nodes don't need resetting as their parent (the group) is resetted)
             nodes.append(node)
diff --git a/plugins/3MFReader/ThreeMFWorkspaceReader.py b/plugins/3MFReader/ThreeMFWorkspaceReader.py
index 40d64590f5..5c62c361c3 100755
--- a/plugins/3MFReader/ThreeMFWorkspaceReader.py
+++ b/plugins/3MFReader/ThreeMFWorkspaceReader.py
@@ -609,7 +609,7 @@ class ThreeMFWorkspaceReader(WorkspaceReader):
 
                         instance_container.setName(self._container_registry.uniqueName(instance_container.getName()))
                         new_changes_container_id = self.getNewId(instance_container.getId())
-                        instance_container._id = new_changes_container_id
+                        instance_container.setMetaDataEntry("id", new_changes_container_id)
 
                         # TODO: we don't know the following is correct or not, need to verify
                         #       AND REFACTOR!!!
diff --git a/plugins/3MFWriter/ThreeMFWriter.py b/plugins/3MFWriter/ThreeMFWriter.py
index 79b821fe31..c4b7035cf1 100644
--- a/plugins/3MFWriter/ThreeMFWriter.py
+++ b/plugins/3MFWriter/ThreeMFWriter.py
@@ -6,8 +6,9 @@ from UM.Math.Vector import Vector
 from UM.Logger import Logger
 from UM.Math.Matrix import Matrix
 from UM.Application import Application
-import UM.Scene.SceneNode
-from cura.Scene.CuraSceneNode import CuraSceneNode
+from UM.Scene.SceneNode import SceneNode
+
+from cura.CuraApplication import CuraApplication
 
 import Savitar
 
@@ -62,11 +63,15 @@ class ThreeMFWriter(MeshWriter):
         self._store_archive = store_archive
 
     ##  Convenience function that converts an Uranium SceneNode object to a SavitarSceneNode
-    #   \returns Uranium Scenen node.
+    #   \returns Uranium Scene node.
     def _convertUMNodeToSavitarNode(self, um_node, transformation = Matrix()):
-        if type(um_node) not in [UM.Scene.SceneNode.SceneNode, CuraSceneNode]:
+        if not isinstance(um_node, SceneNode):
             return None
 
+        active_build_plate_nr = CuraApplication.getInstance().getBuildPlateModel().activeBuildPlate
+        if um_node.callDecoration("getBuildPlateNumber") != active_build_plate_nr:
+            return
+
         savitar_node = Savitar.SceneNode()
 
         node_matrix = um_node.getLocalTransformation()
@@ -97,6 +102,9 @@ class ThreeMFWriter(MeshWriter):
                 savitar_node.setSetting(key, str(stack.getProperty(key, "value")))
 
         for child_node in um_node.getChildren():
+            # only save the nodes on the active build plate
+            if child_node.callDecoration("getBuildPlateNumber") != active_build_plate_nr:
+                continue
             savitar_child_node = self._convertUMNodeToSavitarNode(child_node)
             if savitar_child_node is not None:
                 savitar_node.addChild(savitar_child_node)