This is getting a bit strange. I used your code in both App and Scene Delegate, but wanted to try it without the unique scene identifier. When i switched windows in the simulator I got all the proper notifications when the app went in the background or active and the data was being loaded and saved at the proper times. My test was to add or delete data in one window and then open the other to see if the changes were there. The first time I opened the second window the changes were not there, but if I closed it and reopened it the changes appeared. I take this to mean that the common ItemStore is working. Because I don’t have a real iPad, I am not certain whether I am looking at a real artifact or one related to the simulator. I am not sure that the unique scene identifier is necessary.?