External USB DAC volume control

[octie1968]

Hello, after using Neutron player in my Blackview Alife P1 Pro, while attached to a Fiio K1 external DAC, I am unable to control volume using the smartphone's hardware buttons. Neutron is actually working on the smartphone's internal DAC volume controls, so I have to manually use the preamp bar (trying not to use hardware buttons as they deactive preamp bar). In fact, selecting 'media buttons' and 'media buttons priority' in settings turns out to be fatal for playback (kind of a loop glitch). Maybe if we could choose to use preamp bar in main screen when touching hardware buttons would be OK (in fact as you know, gain bar actually appears when pressed). It seems something only realted to external DACs. Any help welcome. Thanks in advance.