Sorry for the delayed response. Here is the code repository I used for testing:
https://github.com/zhuscat/backgrounddelivery
I log an event whenever a background delivery is received. The logs include details such as the timestamp and whether the app was running in the background.
Here is my testing workflow:
First, I restarted the phone and ensured the battery was fully charged.
I checked the logs periodically and observed that background delivery was received normally throughout the day. This consistent behavior lasted for two or three days.
I continued using the phone normally. On one specific day, I let the battery drop below 10%. The next day, I noticed that I was no longer receiving any background delivery updates (even though I had recharged the battery to 100% and Low Power Mode was disabled). The only difference between this failure state and the previous successful days is that the battery had been drained to a very low level the day before.
Another day passed, and I found that I was still not receiving any background delivery updates.
The only things I know for sure right now are:
Background delivery is not received when Low Power Mode is on.
It is not received if Background App Refresh is disabled in Settings.
However, everything else seems like a black box. At least based on what you said, I should be receiving updates since my battery has remained above 80%, yet I am receiving nothing. I am not sure if this is related to the battery dropping below 10% on the previous day.
Test Device: iPhone 17 (26.2)
