You can switch your system to NetworkManager control with the following instructions.

Netplan is configured in a "yaml" file in `/etc/netplan/`. The configuration file may have different names on different systems. On my install the file name is 01-netcfg.yaml.

Lets make a backup copy of that yaml file and edit the existing one to use NetworkManager.
```
cd /etc/netplan
sudo cp 01-netcfg.yaml 01-netcfg.yaml-backup
```

Now edit `01-netcfg.yaml` using your editor of choice (and use sudo). Change the file so it looks like,

```
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: NetworkManager

```
  

Then run the following to make the new setup:

```
sudo netplan generate
sudo netplan apply
```

Lastly restart the NetworkManager service:

```
sudo systemctl restart NetworkManager.service
```
You are now using NetworkManager.

You'll also need these additional steps:

1. Install [dnsmasq](https://wiki.archlinux.org/index.php/dnsmasq)
2. Configure it (listen address and DNS servers).

Now, install the package:

    sudo apt -y install dnsmasq

Populate the dnsmasq.conf configuration file:

```
sudo su
tee -a /etc/dnsmasq.conf << ENDdm
interface=lo
bind-interfaces
listen-address=127.0.0.1
# DNS server from Cloudflare and Google. Use yours...
server=1.0.0.1
server=8.8.8.8
ENDdm
```
Start the service and enable it at boot:

```
systemctl restart dnsmasq
systemctl enable dnsmasq
```

And now you're all set up.

**PS:** Confirm that NetworkManager's config file is sane, under `/etc/NetworkManager/NetworkManager.conf`.

```
[main]
plugins=ifupdown,keyfile

[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:wwan,except:type:ethernet

[ifupdown]
managed=true
```

Then restart the system.