MariaDB Galera Cluster wsrep_cluster_address not working
You don't provide much information, so I am inferring it from what you say and matching it with a common Galera/Percona XtraDB Cluster/MariaDB Cluster misconception and mistake:


  "shutdown the cluster for maintenance and tried to start it again, only the first node will start"


When you stop the cluster fully (something that shouldn't happen under normal circumstances), you need to start the cluster in reverse order. This means: the last node to be down must be the first to start. Why? Because if you are making changes on all nodes, the last one to go down is the one that will get more ahead of the other regarding the transaction UUID. When you shutdown a node normally, the other nodes survive and continue receiving updates. If you now start and create what it is essentially a new cluster from scratch, galera cannot know that the first node that you start is not the "freshest", because you are bootstraping it.

So in short, always check that you do not bootstrap the cluster on a node that is not the last to get shutdown. If you do not know it, here it is a guide on how to do it (along with other useful information on restarting a Galera cluster and other gotchas).

Hope this helps.