I have changed the mode of operation of a Cluster from "Balanced" to "Active Standby" and all looks good.... The reaseon for this was to enable Dynamic Routing.
I have NOT rebooted any Cluster Engine.
BUT ............... i still get the error (Dynamic routing can only be configured with single node or with standby clustering (online node)) ......when running the (sample-confg) command on the online node.
Is a reboot reqired ??
Starting from 5.7.4 and 5.8.0 it shouldn't require reboot. In older versions like 5.5 you need to reboot after changing clustering mode.