The client list in the wifi router (ubee) lists unknown devices in the client list connected via wifi. So I changed the password and changed it in only one of my machines. After this the client list still shows unknown & known devices with the known devices not yet knowing the new password. I rebooted the router. Of course I hit refresh multiple times. No change. How can this be?
Don't just reboot the router, do a full reset to factory defaults by holding in the reset button for ten seconds. That step clears internal memory before it writes in the factory settings.