I was thinking back and actually I am not sure that it worked in Leap 42.1, but definitely in all earlier versions, since my PC is a rather old Shuttle PC, that have been running OpenSuse all of its life ;-) I have tried the KMP (commenting out the fix in the ifcfg file) and it works when network is using the "wicked" mode. Using Plasma network manager just causes the NIC to connect and disconnect in an endless cycle. So for now its is a fix although I have not noticed any change in connection speed so far.