Dark/black webcam image
On a Dell XPS 13 9370 with Debian sid/unstable and PipeWire 0.3.15-1, a user reported that in Skype and Zoom, the webcam image was more or less black. Some pixels could be seen. Additionally, using Cheese an image could be seen but in black quality. The user reports, killing PipeWire processes helped.
$ lsof | grep video0
pipewire 620 molgenuser 68u CHR 81,0 0t0 439 /dev/video0
pipewire 620 629 pipewire molgenuser 68u CHR 81,0 0t0 439 /dev/video0
$ killall pipewire