I tested 1.20200601+arm64-0ubuntu2~18.04.1 by booting the image from http://cdimage.ubuntu.com/ubuntu-server/bionic/daily-preinstalled/pending/ which already has proposed enabled, and it boots on rpi4-8G as well as my other rpi devices.
I tested 1.20200601+ arm64-0ubuntu2~ 18.04.1 by booting the image from http:// cdimage. ubuntu. com/ubuntu- server/ bionic/ daily-preinstal led/pending/ which already has proposed enabled, and it boots on rpi4-8G as well as my other rpi devices.