disappeared network adapters with nat - virtio BUT works with nat - intel desktop

[bani]

Hi,
suddenly all of my VMs (Windows 2016, 10, 7) under Mojave host, VirtualBox 5.2.22 lost network adapter with NAT adapter setting.
I tried to wipe out the whole install, and roll back to 5.1.x, 5.2.18 as well, no success. Also recreated the VMs (via Vagrant) with the same result.

Attached is the log from one of the VMs. It does seem that NAT works but I don't know what to look for.

Any idea how I could solve this?

UPDATE: just found out that they are actually working 82540EM adapter type, but not with either Virtio, or 82543GC.
I tried to uninstall/reinstall different Virtualbox / Extension Pack combos, but still don't know how to get the VirtIO one working

thank you