We have an app where the notification service extension works well most of the time. However, sometimes we have noticed that the extension completely stops working even when the notification is sent successfully via the APNS server in production. We do not see even the log from the didReceive() function in that case. The only way we can get the extension working again is after restarting the iPhone. Trying to understand when this might happen? Is it something that is throttled by iOS? Would it happen when the device memory is low or the app is using too much memory? We have seen the extension crash sometimes due to hitting memory limits, however, the extension process is spawned again when a new notification comes in. Any kind of help or guidance would be greatly appreciated. Thanks We have setup acknowledgment API calls in the notification service extension processing to be notified when the notifications reach the device. So based on that we know how often the devices stop responding with the ACK to sent notifications. It happens seldom with some users and we have to ask them to restart their device to get the extension functional again.