We have manually (like EAP6) configured colocated topology with shared journal.
Client is connected to server1 and sends messages to queue. While sending, server1 is killed when "processRoute" method is invoked in PostOfficeImpl on server1. Client successfully executes failover sequence to backup. Then server1 is started again.

Client is stuck (probably on send() ) method.
Server1: Live obtains live lock sucesfully, backup obtains backup log sucessfully and is announced, cluster is connected. Log starts spamming messages:
13:53:33,730 WARN [org.apache.activemq.artemis.core.client] (Thread-0 (ActiveMQ-server-org.apache.activemq.artemis.core.server.impl.ActiveMQServerImpl$2@70f35326-1682410692)) AMQ212006: Waiting 2,000 milliseconds before next retry. RetryInterval=2,000 and multiplier=1

Server2: Live and backup are announced and obtain their locks. And in some cases starts spaming log with: 13:47:40,718 WARN [org.apache.activemq.artemis.core.client] (Thread-20 (ActiveMQ-client-global-threads-785057483)) AMQ212006: Waiting 2,000 milliseconds before next retry. RetryInterval=2,000 and multiplier=1

Here are thread dumps from client: [dump-client.txt] and from server1: [dump-server.txt]

In attachment are configs of both servers.