Tiamat 7.1 v2 does not play all channels

Hello, I bought a headset some time ago but I never used 7.1 mode, I decided to use it, but my card does not seem to reproduce the sound for the channels, I updated the sound driver and managed to separate the channels and now the card seems to recognize , when I do a test connecting one cable at a time they work, but when I play a song or video, the sound is played only on the front channel. my motherboard is an asus prime x299-a, will i have to buy a separate sound card to use 7.1 of the phone even if there are all channels? or am I not doing something right? Sorry about my English as a translator.