Network not working for Ubuntu VMs made by virt-builder

Host: Fedora 32

Fedora guests work fine. When using virt-builder and building ubuntu-18.04 (20.04 isn’t in the official repos and I haven’t had time to make a MR there), the booted result doesn’t seem to have any networking capabilities, when attached to the host’s bridge. Doesn’t matter if I use virtio or e1000e.

The VM does however have (host’s) networking while using commands like virt-customize and virt-builder.

I also tried building an image without using any networking at build time, but that didn’t help.
I could set static ips and gateways, but I don’t see how this would help.

Installing manually with the downloaded server iso and installre works, but I think that’s too hard. I could however customize based on the manually installed image, but there’s probably a simple thing I’m missing.

What am I missing here?