Using the arm64 raspberry pi image from http://cdimage.ubuntu.com/ubuntu-core/20/beta/20200514.2/, I often cannot get console-conf to connect on the run mode boot. Console-conf shows there is no dhcp info on eth0 and it is disabled. If I try to enable ipv4 on eth0 interface with console-conf it just spins for a few minutes before I give up and reboot the pi again.
After rebooting, it is then able to get an ip address. This seems to be 100% reproducible for me, the same Pi with classic focal does not have this problem.
This also affects recover mode, in that basically every "first boot" of recover mode fails to get an IP address and so I have to reboot it, then it gets an IP address and I can login via SSH.
Note that this same exact Raspberry Pi 4 with the same network cable and same network and power supply, even SD card doesn't have this problem with UC18 (though obviously the SD card is re-flashed).
HW: rpi4b 4g rev 1 core/20/ beta/20200513. 2/ubuntu- core-20- armhf+raspi. img.xz
Image: ubuntu-
Flashed the image and only eth0 available for network configuration. eth0 is displayed with a MAC address but Uknown Vendor / Unknown model.
Attempt to configure IPv4 DHCP fails to acquire an address.
Completing setup of a static address appears to complete, but the DUT was not ping-able from another device on the network. Attempt to setup user failed.