I am aware Ubuntu 18.04 uses netplan for its networking, and I have a file at /etc/netplan/50-cloud-init.yaml with the following info:
Picture of /etc/netplan/50-cloud-init.yaml
I know the syntax for this file is valid because when I do sudo netplan --debug apply it does not respond with any syntax errors. However, sudo netplan --debug apply does show this:
Picture of sudo netplan --debug apply result
I have no clue what is going and why Ubuntu decided to switch to this system. However, I suspect DEBUG:device enp0s10f0 operstate is unknown, not replugging is the issue here. Your advice would be appreciated. Thank you.
enp0s10f0
is actually the interface name on your device? That doesn't look like your normal network interface naming in modern Ubuntu environmenst. Also please pay attention to the fact that giving us screenshots of text is less useful than actually giving us the text itself.