Hifiberry soundcard appears to have 7 inputs/outputs

Connecting my hifiberry dacplusadcpro soundcard, I can see 7 different input & outputs. The soundcard is supposed to be stereo 2x2 channels. Trying to connect any of those I/O does not provide any sound, although the soundcard seems to be active (red leds ON). Does anyone else have such an issue? Any suggestions? I am on bookworm 64bit.