I’m still trying to wrap my head around the whole flow of messages & APIs. But one quick thought I had: are the connections being churned at all? As in, as soon as a test finishes are the connections torn down and re-established for the next test? Thinking here: the ackMessage() is not synchronous to the broker… it is an async call that will be transmitted back to the broker to remove the message off the queue on the next “transport ack” by the API, which should be at least once a second. I’ve run into issues before where a Guaranteed consumer will receive a message off a queue, ACK it, and then disconnect right away… and the ACK hasn’t propagated out of the API to the broker, so the message is still sitting on the queue. So a well behaving app should stop consuming and pause for a sec before disconnecting from the broker.
Any chance that’s what could be happening?