Hi,
Can you put a log statement in when invoking notifyReceive and print messageId and delivery ID in logs?
If you are using classic version, go to technical workflow and execute pending-tracking workflow and let see it should fix your problem.
It looks like you are not invoking the notifyReceive on right time or you are getting some NeolaneException exception. Check your logs and let us know, we can help you fix this.
Regards,
Amit