The regedit way seems to have sorted this.

Win10 ver 1803 laptop connected to router by ethernet cable.
Network type is shown as public.
Going through settings and clicking on the network should give a screen with the top section being...

So does homegroup give no advantages over 'normal' networking?

I have two laptops on my network, one wireless, one cabled.
Network and sharing centre, homegroups, says on the wireless one 'available to join' and if I try to join it says the homegroup is on the...