nunchuckmadness; Uh Huh

Yaml files must be exact. We best see what your present file is !
Unfortunate for you - I do not run network manager thus I can not directly check all your files.
However, we can start the looking.
Code:
cat /etc/netplan/01-network-manager-all.yaml
and make sure !
The desktop install -not SERVER - should be this:
Code:
# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager
This - even to the tab/spaces - must be exact !

longest journey -- starts with the 1st step