Some students have set their preferences to 'single daily digest'
email of forum posts and so are not always getting notifications. Set this to single email per post so that you receive them
correctly (under your profile settings).
Also please install the Moodle Mobile app on your iPads and phones - it's free and available for Apple & Android devices. When you do, under App Settings/Synchronization, make sure that "Allow sync only when on Wi-Fi" is NOT enabled (i.e. not green).