Sping .jms.listener blocking another listener from reading JMS message

Question

I have two applications Apple and Pear that uses the above class to listen on a configured JMS queue in WildFly ( 10.1.0 ). The Spring configuration is shown below.

<bean id="appleMessageListenerContainer"
    class="org.springframework.jms.listener.DefaultMessageListenerContainer"
    depends-on="transactionManager">
    <property name="connectionFactory" ref="connectionFactory" />
    <property name="destination" ref="outQueue" />
    <property name="destinationResolver" ref="jmsDestinationResolver" />
    <property name="messageListener" ref="AppleMessageListener" />
    <property name="messageSelector" value="ID='APPLE_ID'" />
    <property name="transactionManager" ref="transactionManager" />
</bean>

<bean id="pearMessageListenerContainer"
    class="org.springframework.jms.listener.DefaultMessageListenerContainer"
    depends-on="transactionManager">
    <property name="connectionFactory" ref="connectionFactory" />
    <property name="destination" ref="outQueue" />
    <property name="destinationResolver" ref="jmsDestinationResolver" />
    <property name="messageListener" ref="PearMessageListener" />
    <property name="messageSelector" value="ID='PEAR_ID'" />
    <property name="transactionManager" ref="transactionManager" />
</bean>

The expected process is as follows :-

Apple application listener ( AppleMessageListener ) will read a message from a "outQueue" JMS queue. The message is updated and the AppleMessageListener will write the message out to the "outQueue" with the senderId set to "PEAR_ID", so that the PearMessageListener will read the message. The AppleMessageListener will wait for a response from Pear application on different "inQueue" or timeout.

Unfortunately, what happens is that the AppleMessageListener writes the message to "outQueue". The AppleMessageListener times out waiting for a response. Only after this timeout does the PearMessageListener read the message from the "outQueue". It is as if whilst the AppleMessageListener is waiting for a response, the PearMessageListener is prevented from reading the message.

Any thoughts on why this is the case please. Thank you for your help.

Pete