After every restart i loose my "notification sound" on Mi MESSAGER.
I have my one sound which is stored under "Ringtones/"
Does anybody see the same?
Sort of.
With SMS messaging, if I use a non-system sound for the notification, it doesn't work after a reboot.
If I use a system sound, it works OK after the reboot.
From recent experience, it could be the same with Skype and WhatsApp because their notification sounds have also stopped working. I use non-system sounds for them also. (It's the middle of the night so I cannot get anyone to test them!)