Pipewire ignores multiple channels input from audio interface

[phaabe]

I am new to the topic.

In my specific case of a USB audio interface with 12 input channel, pipewire does only take the first two channels into account.
Is that something the user must configure when in there are more than two channels for stereo?
or is that normally "automatically" detected?

Environment:
PopOS 22.04 LTS
Pipewire 1.0.3
Tascam Model 12, firmware v1.42
Bitwig 5.2.3

Further notes:

• ALSA driver serves all channels to Bitwig
• I tried messing with pipewire settings, but it doesn't feel very comfortable as I don't know enough.