Simulatenous Playback and Recording to External USB Sound Card Does Not Work

Hi,

I'm trying to migrate my audio producing workflow from Jack to Pipewire. I have a Synth that acts as an audio interface. When I try to connect input and output ports to a client via Pipewire (either with qjackctl graph or Catia), Pipewire goes into a non-functioning state.

Connecting either input or output without the other one works fine.

The log output (via journalctl --user -f -u pipewire -x) is the following:

Feb 20 19:25:04 jonas-laptop-arch pipewire[5822]: set_hw_params: Device or resource busy
Feb 20 19:25:04 jonas-laptop-arch pipewire[5822]: (alsa_input.usb-Yamaha_Corporation_MODX-00.pro-input-0-50) start node error -16: Device or resource busy
Feb 20 19:25:09 jonas-laptop-arch pipewire[5822]: set_hw_params: Device or resource busy
Feb 20 19:25:09 jonas-laptop-arch pipewire[5822]: (alsa_input.usb-Yamaha_Corporation_MODX-00.pro-input-0-50) start node error -16: Device or resource busy

Feb 20 19:24:53 jonas-laptop-arch pipewire[1250]: set_hw_params: Device or resource busy
Feb 20 19:24:53 jonas-laptop-arch pipewire[1250]: (alsa_output.usb-Yamaha_Corporation_MODX-00.pro-output-0-49) start node error -16: Device or resource busy
Feb 20 19:24:53 jonas-laptop-arch pipewire[1250]: set_hw_params: Device or resource busy
Feb 20 19:24:53 jonas-laptop-arch pipewire[1250]: (alsa_output.usb-Yamaha_Corporation_MODX-00.pro-output-0-49) start node error -16: Device or resource busy

The device that is reported to be busy is usually the one that I connected last. The workflow used to work with Jack, so I don't think it is an ALSA issue.

System information:

Arch Linux, 5.10.16-arch1-1, 64bit
Pipewire 0.3.22

Alsa cards:

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: MODX [MODX], device 0: USB Audio [USB Audio]
    Subdevices: 0/1
    Subdevice #0: subdevice #0
[...]

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: MODX [MODX], device 0: USB Audio [USB Audio]
    Subdevices: 1/1
    Subdevice #0: subdevice #0
[...]

If you need any further information, please let me know! Thank you very much in advance!