Comment 4 for bug 1800668

Verification-done for both bionic and cosmic:

ubuntu@humble-cod:~$ dpkg -l netplan.io | grep ii
ii netplan.io 0.96-0ubuntu0.18.04.1 amd64 YAML network configuration abstraction for various backends

ubuntu@superb-ram:~$ dpkg -l netplan.io | grep ii
ii netplan.io 0.96-0ubuntu0.18.10.1 amd64 YAML network configuration abstraction for various backends

Opening the netplan manpage, in under the 'mtu' section it is now clearly stated:

"""
             Note: This will not work reliably for devices matched by name only and rendered by networkd, due to interactions with de‐
              vice renaming in udev. Match devices by MAC when setting MTU.
"""