From the github page (https://github.com/raspberrypi/rpi-eeprom/issues/28) you can see that this needs an updated firmware which you can install via rpi-update. Never used Ubuntu on the Pi only raspbian, but I am sure they also have those rpi tools. How does Ubuntu run on the Pi work? I never got passed installation, because after install the first boot just hangs. It seems to me it wants to install additional stuff via ethernet which in my case is not attached and I never had the option to configure wifi....

It’s not clear what method you used but for the benefit of others: Don’t install Ubuntu, it doesn’t have the needed closed source firmware blobs and isn’t compiled with some of the kernel modules the Pi uses. Instead burn a copy of the preinstalled Ubuntu Raspberry Pi disk images to an SD card.

Downloads here: https://ubuntu.com/download/raspberry-pi

64-bit is only supported on newer 3B and 4 devices and is missing some Pi-specific features.

Hmm, I'll have to check it out.

I think it works great. Using the 64 bit 20.04 and now 20.04.1, I've had no problems with my 4 4Gb Pi4s (so many 4s!). You should be able to set up the wifi using netplan, although I do only run mine wired so haven't tried it.