I've been using the Apple Smart Battery Case on my iPhone 6S for the past few weeks to hold me over until I can get the iPhone battery replaced, because it's dying. The case has been working great for a while now.
Last night I upgraded to iOS 13.0, and now my iPhone no longer connects to the Smart Battery Case at all. It just doesn't show up under the batteries list that you can see if you swipe left from the Notifications Center, it doesn't charge the phone, etc.
I know that the battery case is fully charged because it shows a green light when I plug it in.
I have turned off the new Optimized Battery Charging feature to see if that would help, but it didn't.
Can you think of anything else I can try?