audio becomes metallic during streaming

[Vayshya]

TV streaming server based on VLC works perfectly for weaks. It takes video from TV tuner.
There is one problem left: sometimes sound becomes metallic, it often happends after moments of heavy load of server, for example start or activity of other programs.
This problem was exactly same in Unreal Media Server 4 (old version). They tell that in version 5 problem with sound from TV tuner is fixed and i could not reproduce this case there.