Is it getting its configuration from some central location? It may be that in that central INI file it is being setup to hide the connection manager. You can either try to set the device to factory defaults and/or unplug from network when you boot up. This will ensure it doesnt get any central configuration so you can edit as you wish first. Of course, if you still have that central file, once you plug into the network it will receive whatever configuration is there--as designed. So best to check for that central config first