Apache Artemis - Messages from same group-id are received by multiple consumers - spring-boot

Question

I have two deployed apps, one on my local machine and one on the server. Both apps are communicating through the same Artemis client, which is installed on the server. Artemis version is 1.5.5.
The problem occurs when I execute a simple test that sends 1000 messages divided into multiple groups, in this case 50 groups (numbers are not important, it happens no matter the number of messages or groups) from the server app. The local app consumer receives every group and almost all messages. It's because the server app consumer receives, for example, only one message from - let's say - group number 5. That behavior is repeated in multiple groups.
Why is this happening? Again, both consumers and producers are working on the same Artemis. Apps are written in Spring boot. The local app is deployed using Spring's bootRun task, while the server app is deployed in Wildfly-11.0.0.Final.
Here is my broker.xml file:
<configuration xmlns="urn:activemq" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:activemq /schema/artemis-configuration.xsd">
<jms xmlns="urn:activemq:jms">
<queue name="DLQ"/>
<queue name="ExpiryQueue"/>
<queue name="AlarmsQueue"/>
</jms>
<core xmlns="urn:activemq:core">
<name>0.0.0.0</name>
<persistence-enabled>true</persistence-enabled>
<!-- this could be ASYNCIO or NIO
-->
<journal-type>ASYNCIO</journal-type>
<paging-directory>./data/paging</paging-directory>
<bindings-directory>./data/bindings</bindings-directory>
<journal-directory>./data/journal</journal-directory>
<large-messages-directory>./data/large-messages</large-messages-directory>
<journal-datasync>true</journal-datasync>
<journal-min-files>2</journal-min-files>
<journal-pool-files>-1</journal-pool-files>
<!--
This value was determined through a calculation.
Your system could perform 8.06 writes per millisecond
on the current journal configuration.
That translates as a sync write every 124000 nanoseconds
-->
<journal-buffer-timeout>124000</journal-buffer-timeout>
<!-- how often we are looking for how many bytes are being used on the disk in ms -->
<disk-scan-period>5000</disk-scan-period>
<!-- once the disk hits this limit the system will block, or close the connection in certain protocols
that won't support flow control. -->
<max-disk-usage>95</max-disk-usage>
<!-- the system will enter into page mode once you hit this limit.
This is an estimate in bytes of how much the messages are using in memory -->
<global-max-size>104857600</global-max-size>
<acceptors>
<!-- Default ActiveMQ Artemis Acceptor. Multi-protocol adapter. Currently supports ActiveMQ Artemis Core, OpenWire, STOMP, AMQP, MQTT, and HornetQ Core. -->
<!-- performance tests have shown that openWire performs best with these buffer sizes -->
<acceptor name="artemis">tcp://0.0.0.0:61616?tcpSendBufferSize=1048576;tcpReceiveBufferSize=1048576</acceptor>
<!-- AMQP Acceptor. Listens on default AMQP port for AMQP traffic.-->
<acceptor name="amqp">tcp://0.0.0.0:5672?protocols=AMQP</acceptor>
<!-- STOMP Acceptor. -->
<acceptor name="stomp">tcp://0.0.0.0:61613?protocols=STOMP</acceptor>
<!-- HornetQ Compatibility Acceptor. Enables HornetQ Core and STOMP for legacy HornetQ clients. -->
<acceptor name="hornetq">tcp://0.0.0.0:5445?protocols=HORNETQ,STOMP</acceptor>
<!-- MQTT Acceptor -->
<acceptor name="mqtt">tcp://0.0.0.0:1883?protocols=MQTT</acceptor>
</acceptors>
<security-settings>
<security-setting match="#">
<permission type="createNonDurableQueue" roles="guest"/>
<permission type="deleteNonDurableQueue" roles="guest"/>
<permission type="createDurableQueue" roles="guest"/>
<permission type="deleteDurableQueue" roles="guest"/>
<permission type="consume" roles="guest"/>
<permission type="browse" roles="guest"/>
<permission type="send" roles="guest"/>
<!-- we need this otherwise ./artemis data imp wouldn't work -->
<permission type="manage" roles="guest"/>
</security-setting>
</security-settings>
<address-settings>
<!--default for catch all-->
<address-setting match="#">
<dead-letter-address>jms.queue.DLQ</dead-letter-address>
<expiry-address>jms.queue.ExpiryQueue</expiry-address>
<redelivery-delay>0</redelivery-delay>
<!-- with -1 only the global-max-size is in use for limiting -->
<max-size-bytes>-1</max-size-bytes>
<message-counter-history-day-limit>10</message-counter-history-day-limit>
<address-full-policy>PAGE</address-full-policy>
</address-setting>
</address-settings>
<connectors>
<connector name="netty-connector">tcp://<ip>:61616</connector>
</connectors>
<ha-policy/>
<broadcast-groups>
<broadcast-group name="my-broadcast-group">
<group-address>${udp-address:<ip>}</group-address>
<group-port>9876</group-port>
<broadcast-period>2000</broadcast-period>
<connector-ref>netty-connector</connector-ref>
</broadcast-group>
</broadcast-groups>
<discovery-groups>
<discovery-group name="my-discovery-group">
<group-address>${udp-address:<ip>}</group-address>
<group-port>9876</group-port>
<refresh-timeout>10000</refresh-timeout>
</discovery-group>
</discovery-groups>
<cluster-connections>
<cluster-connection name="my-cluster">
<address>jms</address>
<connector-ref>netty-connector</connector-ref>
<retry-interval>500</retry-interval>
<message-load-balancing>STRICT</message-load-balancing>
<max-hops>1</max-hops>
<discovery-group-ref discovery-group-name="my-discovery-group"/>
</cluster-connection>
</cluster-connections>
</core>
</configuration>