HDMI. low sound quality (no treble)

When you connect the Pioneer receiver to your PC, you get great sound. Audio output via HDMI graphics card GTX 1070. But when I connect the receiver to volumio (raspberry Pi 3A+) and turn on the same songs from the usb card, the quality is terrible - the upper frequencies disappear. I also connect raspberry via HDMI. Where is the promised audiophile sound???