Tw WP Reliable Cookie Bar, when a user clicks on the “accept” button saves the information into the browser localStorage.
Some cookie bars save the information into the cookies. Cookies are sometimes cleared by the users, because of some issues, or different reasons. If a person clears often the cookies, each time they enter your website will see the cookie bar back again. However with this cookie bar, they will not see it again, unless they clear the localStorage automatically or manually.
The localStorage does not expire.