795 sound plays through speaker/sometimes not works headset buttons

[Skiph]

Phone: Asus ZenFone 5 ZE620KL (Firmware version: OPR1.170623.032.WW_Phone-15.0619.1807.31)
Headset: Xiaomi Mi In-Ear Headphones Pro HD

1) Sometimes, when headphones connected to the phone and Hi-Res output enabled, the sound can start play trough speakers. This happens randomly. Only helps to reboot device and launch player again, after this it works fine.
I tried to disable DVC and seems it helps, but sound became quieter and not detailed as before. Is it only one solution to fix?

2)  Sometimes buttons Play/Pause not works on headset on lock-screen. When I unlock screen and back to the player, I push Play/Pause button again on headset and after this it works as expected even on lock-screen.