Reproduction steps:

• Bring up an ActiveMQ Artemis 2.27.0 broker, with a queue (anycast in our case)
• Use JMS to send a text-message from Java code, with a JMS property (header) with key equal to a non-empty string and with value (string property) set to NULL. The message is added to the queue.
• Use STOMP (we use stomp.py) to subscribe to the queue with the text-message on it. The message will not be received, apparently because of the null value in the JMS property (header). At the default logging level no issue is reported by ActiveMQ Artemis. Also via the STOMP protocol no error is received. Any messages that are added to the queue which do not have headers with a NULL value are received properly via STOMP.

Note: we haven't tested what happens if the key is NULL and the value is not

Workaround:

• Use a value unequal to NULL for the value of each JMS property (header)