I am on a iPhone 13 and all my friends are missing and same with chat I have cleared cache uninstalled and reinstalled and trying no Wi-Fi to Wi-Fi same issue been like this last 4 days
Go into settings general iPhone storage go to auhenticator and tap offload app then go to battle.net and tap offload then reinstall both and sign in worked for me
Samsung s22 ultra and its still or again not working