I’m using an iPhone 11 Pro Max and my girlfriend uses an iPhone 7 Plus. We both open the game and I see her on my friends list as online. She leaves her phone for a while, it locks, and she becomes online on my friends list. She unlocks her phone with the game still active but she still appears offline in my friends list. She sends a challenge invite to me and I receive it, but when I tap on it (bottom left corner of the screen), the challenge disappears and she stills appear offline. She has to restart the game to make her appear online in my friends list.