Mine does the same thing. Didn't glitch off at first. Must have been something you broke in an update.
new update yesterday... did all you steps and still turns off when closing. If you don't fix it I want my money back and you can have it.
I downloaded the rapid ring, app so lets hope this works as a temp fix. However I recomend leaving a review on the app in the app store. Instead of here were the developers more than likely dont see the complaints. If you leave a review in the app store developers can respond directly to your comments( if they want to is another issue). If the app rating starts dropping enough from the reviews they will have to take action. I gave it a 1 star just for this issue. What is the point if if you cant get the notifications. I recomend everyone on here do the same especially since a new version came out yesterday.
I have the same issue after I installed the device yesterday. I called support this morning, they said they are aware of the software issue & are working on it. I sure hope they are since many people are having the same issue. I left a review on the apple store & here on the thread.