Comment # 1 on bug 1027742 from Larry Finger

I could not duplicate your setup, but I think I got close. This is what I did.

1. I installed VB on a fully updated Leap 42.2 system. That was normal other
than the build system has failed to build the kernel modules for the latest
kernel, thus I had to install the VB source and build the modules separately.
2. I created two identical Leap 42.2 guests with NAT networking and updated
them.
3. From File=>Preferences=>Network, I created the host-only interface.
4. I converted each of the two VMs to use the host only interface created
above.
5. After booting the two VMs, they could ping each other and the host. It seems
that the networks were working. Wicked was controlling the interfaces.

What did you do differently other than using TW as the host?