Do you have a Mac with an Intel chip or an M1? If you have an M1 chip, my experience is that it doesn't work. The software runs, but the signal from the camera doesn't appear. If you have an Intel chip, it may work.
I'm having the exact same issue, the only difference is my camera (EOS 6D, with latest firmware). I've tried a couple different cables, no luck. On an older, Intel-chipped Mac, with the older version of EOS Webcam utility, it does work -- so I know i...