Please read my message below
As a good start i solved the problem with Clash Royale. Please download "Miui Hidden Settings" from Playstore, start the app, select Manage Notifications, select your app (that there is no sound) and look for "No sound" or "Make sound" mark. If it is "No sound", it means stuck on mute. Go to Playstore download Autonotification, start the app, watch the ad to use the app, give Notification Access, go to notification categories, pick your app, switch the option to Make Sound. Check if it is ok with Miui Hidden Settings then remove Autonotification if you want.
10-08-2018 04:42 PM