When publishing Persistent (Guaranteed) messages, the API will automatically resend Persistent messages if it has not received an ACK (acknowledgement) from the Solace broker within 2 seconds. (I think, pretty sure 2 seconds). You wouldn’t see anything in the broker’s event log. This is just a notification (not an error) from the publisher API saying that it didn’t hear back from previous messages and was resending. Note that this will not cause duplicate messages on the broker… the broker and API are smart enough to de-duplicate any retransmitted messages.
Hope that helps!