Ubuntu server default password using Raspberry Pi image?

I've just installed Ubuntu Server on my Raspberry Pi 2 B and the download page says that the default username and password are both "ubuntu", but the system says that the password is incorrect. What's wrong?

I found that it takes a few minutes after it boots for Ubuntu on the Pi to create the 'ubuntu' user and its password.

I searched for a solution and found this question. The existing answer was no help. When I went back, some text had come up on the console about cloud init and SSH keygen. I tried again, and ubuntu:ubuntu worked!

Try these:

1) You can SSH into the Pi 4 with:
User: ubuntu
Pass: ubuntu

* It will then ask for new password. *
This only works if you have ethernet cable connected.

Source: https://www.raspberrypi.org/forums/viewtopic.php?t=254649

2) and try ..has the default username pi and default password raspberry

3) The default password is root which you can easily change once you are booted into the Pi by running 'passwd' command. Source: https://www.linux.com/tutorials/getting-started-raspberry-pi-2-install-linux-and-access-ssh/