remote notifications only work when app is started from xcode

In my CloudKit application, everything works just fine in the first place. My app establishes a subscription which fires remote notifications everytime a record has changed - so far, so good.

The problem is: the remote notifications get delivered to my iPad only if I run the app right out of Xcode. If I run the app from HOME, the notifications do not reach the iPad, although the server‘s log tells me that the notification was fired (and reaches other devices).

Can anyone give me a clue why the remote notifications only work when the app is run from Xcode? This is strange.


(Could this be an iOS11 issue?)