redmi 2 current version stops ringtone sound and media sound

the internal sounds provided by rom do not work sometimes, but sometimes it works as I installed new rom and now the sound is working fine, there is surely a bug in the current rom of redmi 2(MK71.2-wt88047-201802061843-NIGHTLY). pls update as much as possible except this thing other features are up to mark. but still, we can’t use it as it is a major bug. not a good idea to continue with it as sometimes phone ringtone doesn’t ring(I have also checked all default profile sound settings, every setting is right.)