The answer which the user gives to the redirect pop-up is stored in the current session. The session is a temporary entity, and once the session is destroyed - the extension has no source of information on the preferred redirect of the particular user so it will show a pop-up again.
By default Magento has the session time limit at around 15 minutes. This duration can be configured in the store's backend admin panel according to the requirements. Here is the detailed Magento guide on how to do it on the Magento Commerce User Guide