in the IOS18.1 release when using Apple Intelligence the notifications will be delayed around 10 second. Even without the notification summary turned on. It seems to be a system-wide bug, anyway to fix it or bypass it.
Ios18.1 notification delay with Apple Intelligence
With the Okta it's more around 30 seconds... The notification is received by the app immediately as its badge count changes, or if the app was already on screen it appears immediately. But if the phone is at the lock screen and/or home screen and/or running other apps, the notification is delayed by at least 30 seconds.