If you close that pop up before, it will no longer appear again is because our system will check if this guest user current session id close this pop up before, it will just ignore it and it will not appear again.
To verify this again, you can try truncate this table '#__session' data from your database before you test.
One more thing is if the page is login and registration page, this pop up will not show up as well.
If you do not want this session thing checking, you can download my attached screenshot below and replace to the same file location.