Creator Update and HomeGroup Issue

Prior to the update I had no issues:
4 computers connected via wireless to a New Netgear Router.
Prior to update, all computers were recognized on the network and the Homegroup.

1) 3 computers see all on the network and Home Group and can access each other and can see the 4th computer on network and Home Group and access the 4th computer shared files and drives.

2) Prior to the update computer 3 and 4 were set up for file history back up to #1 computer external hard drive

3) after the update the 4th computer cannot access the Home group although it has joined the Home group and displays "no other Home group PC's are available right now". All other computers see it and can access it.

4) Computer 3 and 4 cannot back up file history via network to #1 external hard drive although the ext HD can be accessed and read write to the ext HDD

I have tried "All" the usual "fixes" Network settings, home group settings, change permissions on MachineKeys folder etc.. IpV6 enabled and on and on.

Banging my head on the wall. Maybe have to just stick to networking and forget a Home Group.