Short answer: notifications not showing after an iOS 27 update is usually not a broken push channel — it is something quietly intercepting them. A Focus mode filtered a layer, an app's notification permission got re-asked after the update, or Scheduled Summary turned instant delivery into a batched digest.
So the first step is not fixing the system but separating "never arrived" from "arrived but never alerted you": the first is an app and account question, the second is a Focus and notification-settings question.
Separate the two kinds of "no notifications"
These have completely different causes, and mixing them up wastes a lot of time:
| What you see | What is actually happening | Where to look |
|---|---|---|
| You only see new messages after opening the app, no badge | Genuinely not delivered | App permission, background refresh, in-app switches |
| No sound or wake on the lock screen, but notifications are all in Notification Center | Delivered, but not surfaced | Focus, Scheduled Summary, the allowed list |
| Only one app is silent, everything else works | A single app problem | That app's settings and version |
| No notifications at all, including Messages and calls | System-level or connectivity | Focus, Do Not Disturb, network, restart |
Get that classification right first, and the rest of the search has a direction.
Push and Background App Refresh are two different things
This deserves its own section because it is the most common mix-up. Push is Apple's system-level channel: the app's server hands the message to Apple, Apple delivers it to your phone, and iOS shows the notification directly. Background App Refresh is something else — it decides whether an app may wake on its own and fetch new data while you are not using it.
The conclusion: turning Background App Refresh off does not make you miss pushes. Turning it off to save battery is safe (the mechanism is explained in What is Background App Refresh?). Conversely, if pushes genuinely broke, turning background refresh off will not help at all — the places to check are below.
The check order
① Focus modes. Settings → Focus, and look for any active mode (Do Not Disturb, Work, Sleep, Personal). A Focus filters notifications by its allowed list, and anything not on it is silenced. Check the allowed people and apps inside each mode — this is the most common reason notifications look "hidden".
② Scheduled Summary. Settings → Notifications → Scheduled Summary. If it is on, apps included in the summary have their notifications collected and delivered at set times, which feels exactly like "notifications stopped". Move the important apps out of the summary.
③ Per-app notification permission. Settings → Notifications → the app → confirm Allow Notifications is on and the alert style is not None. An update occasionally re-asks for permission, and if you dismissed it with "Don't Allow", it stays off.
④ The app's own switches. Many apps have a second layer of settings (such as "notify over Wi-Fi only" or "mute messages"). System settings being correct does not mean the app's own switches are on.
⑤ Update the app. Right after a major release, third-party apps adapt on different schedules, and updating them all to the latest version is the cheapest move.
⑥ Restart the phone. A normal power off and on is enough. If every app is silent, including Messages and calls, a restart is the highest-value step; if that still fails, see How to force restart a stuck iPhone.
When it is genuinely a problem
- System-level notifications such as Messages and calls are silent too, and a restart does not help — that is closer to a system issue; consider updating to the latest minor version or having Apple check the device;
- one app never pushes, even after reinstalling — the problem is that app's server or adaptation, and contacting its developer beats fiddling with the phone;
- notifications arrive very late, and are fine on Wi-Fi — mobile network or power-saving policy is likely holding background work back; check whether Low Power Mode is on, see What is Low Power Mode?;
- notifications work but battery drain got much worse — the bottleneck is not notifications; see iOS 27 battery drain after update.
One warning to close on: do not install unknown configuration profiles or tools to "fix push". Push is an Apple system-level channel, and any third-party claim of "boosting" or "repairing" push is not trustworthy. The real entry points are the six system settings above.