You get the message when you have e.g.your ASG running in a cluster and some of the notes are down, e.g. if you have 2 nodes in your cluster and one is down you will get the message.
Actually, this is a warning you should take seriously - please check your Cluster nodes for any malfunctioning systems. It is not about getting rid off the message but correcting the problem which ACC reports.
please post your HA/Cluster related questions in the respective ASG forum. ACC is just reporting the status but does not in any way influence whether nodes become unlinked.