Hi Eric,
I had an expert review your question and was able to get an explanation for you. When you close a statistic and reopen it then yes it would reset to zero, it would be assigned a new UserReqID and start fresh.
When you close the stat it stops monitoring the object(s) it was monitoring.
If you think about it, it needs to work this way otherwise the stat would be missing data from the time it was closed until it was reopened.
If you have any follow up questions, please open up a Case with the Genesys Customer Care team and we can dive a little deeper and perhaps discuss in real-time.
Thanks, Neil