Iphone Notifications Not Working When Locked. Unfortunately, some users are not happy with its performance and encountered some bugs like ios 15/14/13/12 notifications not working issue. Then scheduled summary >> then disable scheduled summary for all apps or important apps.
The most basic method to resolve the iphone notifications issue is to restart the iphone immediately. Here, go to messages and make sure that the show on lock screen toggle is turned on and green. If you have the do not disturb option enabled on your iphone, it will stop your iphone from receiving alerts or notifications when the screen is locked.