I'm trying to use the official ubuntu-18.04-preinstalled-server-armhf+raspi2.img.xz image on my Raspberry PI 3B+. I've followed these instructions: https://wiki.ubuntu.com/ARM/RaspberryPi#Booting_the_official_Pi_2_image_on_the_Pi_3B.2F3B.2B- to convert the image for use on my Pi 3B+.
I can get the machine to boot, but it gets stuck in the boot sequence. The first error is that it fails to load kernel modules. After continuing on, the Pi gets stuck during cloud-init and fails to start the networking service.
I've tried manually copying the kernel modules using these commands in the documentation:
sudo cp /boot/vmlinuz /boot/firmware/ sudo cp /boot/initrd.img /boot/firmware/
But still, no luck. Any ideas?