Notifications alter the appearance differently depending on whether the iPhone is in a locked or unlocked state. Restarting the iPhone does not affect the way notifications are displayed.
However, the specific conditions under which you have tested the notification preview displays haven't been clarified.
- Settings > Notifications > Show Previews > Always --> Valid for all Notifications
- Settings > Notifications > Mail > Show Previews and then select Always --> Valid for Mail Notifications only
In general, the more specific settings take precedence over the more general ones:
- Settings > Notifications > Mail > Show Previews (Always): This is a specific setting for Mail notifications, and it will take precedence over the general setting.
- Settings > Notifications > Show Previews (Always): This is a general setting for all notifications. However, since you've specified a more specific setting for Mail notifications, the Mail-specific setting will override the general one for Mail notifications.
So, in this case, the "Show Previews" setting set to "Always" under "Settings > Notifications > Mail" will be valid for Mail notifications, and for other notifications, the general setting under "Settings > Notifications > Show Previews" will be applied.