The latest iOS, iPadOS, and macOS updates are delaying notifications if you have Apple Intelligence turned on and ‘Summarize previews’ turned off. There’s no fix available yet, except turning off Apple Intelligence entirely.
Apple released macOS 15.1 Sequoia, iOS 18.1, and iPadOS 18.1 near the end of October with the first Apple Intelligence features, powered by on-device and cloud generative models. One of the new features is the ability to summarize long notifications as they arrive. There can be a short delay with this feature enabled, as your device processes the complete text contents and trims it down.
However, even if you turn off ‘Summarize previews’ feature (or don’t enable it during the initial Apple Intelligence setup), there can still be a delay with receiving notifications. I noticed this on my Mac after updating to macOS 15.1—I would get a new message in Discord or Slack with an unread indicator in my dock, but not see the notification pop up until several seconds later.
The only fix for the delayed notifications is to turn off Apple Intelligence entirely. You can do that by opening the Settings app (called “System Settings” on Mac), selecting the “Apple Intelligence & Siri” menu, and turning it off. This also means you lose all other Apple Intelligence features until you turn it back on, such as Writing Tools and email summarization in the Mail app.
I’m not the only one running into this bug. One person on the MacRumors Forums explained, “I have notifications for local apps like Transmit and Handbrake. The notification when something in complete, can be delayed by 4-5 seconds.” Another person on Reddit was “experiencing severely delayed notifications using the Gmail and the built-in Mail app,” with several confirmations from other Apple device owners in the comments.
Hopefully, Apple will fix this bug soon, perhaps in the iOS 18.2 and macOS 15.2 updates that are already in beta testing. There are many aspects of Apple Intelligence that don’t seem fully baked, but this bug affects notifications even when it’s not supposed to be changing them.