The documentation reporting to Change the cluster MTU here:
- https://docs.openshift.com/container-platform/4.14/networking/changing-cluster-network-mtu.html#nw-cluster-mtu-change_changing-cluster-network-mtu

Is reporting incorrect checks at point 8.b causing confusion to customer. 

Checks are reporting:

~~~
If the machine config is successfully deployed, the previous output contains the /etc/NetworkManager/system-connections/<connection_name> file path.

The machine config must not contain the ExecStart=/usr/local/bin/mtu-migration.sh line.
~~~

But the files to check in reality are "/etc/NetworkManager/conf.d/" and the "ExecStart=/usr/local/bin/mtu-migration.sh" is expected to be present at this stage, it is removed only after point 10.

4.14 but probably all the supported releases.