The weird part:There are no notifications on the screen when it happens.No icons in the status bar.Even after a restart, the sound came back.It’s a long sound like old alarm clock, not just a short "beep".What I have already tried/checked:Notification History: I checked, but nothing shows up at the time of the sound.Security App: I cleared the cache and data of the built-in Xiaomi Security app.Antivirus: I installed Avast to scan for malware (nothing found so far).NFC: I've...Read more