The fix in https://github.com/openshift/machine-config-operator/pull/1914 addresses three problems: - race condition between dhclient having 64-characters hostnames that are too long for the cluster - slow transient hostname from reverse DNS - network manager failing to set hostname when the dhcp client name is too long - /etc/hostname have a name longer than 63 characters.
*** Bug 1855392 has been marked as a duplicate of this bug. ***
Closing this bug since cherry-pick to 4.3 has been closed. 4.3 is now in maintenance mode. Affected users are advised to upgrade.