Convert To Group Node only available in current session

It seems that when I (Convert To Group Node) works fine up until you reload the workflow after restarting the server where it says the group node is missing so it only exists in the current session. Is this a bug? because it doesn't make sense at all. Also, those groups can be saved as template but they won't save at all. Nothing happens if you save a group node as a template and try to reload it.