Zigbee CC2531 sniffer successfully installed, but no working device found

On my Linux iMac I have flashed 2 x CC2531 Zigbee dongles successfully (I believe), following this manual: https://www.zigbee2mqtt.io/advanced/zigbee/04_sniff_zigbee_traffic.html I needed to install this extra package, which was not mentioned in that manual: apt-get install libusb-1.0-0-dev It's Ubuntu 22.04 on an iMac from 2013. They seem to work: lsusb | grep -i cc Bus 003 Device 033: ID 0451:16a8 Texas Instruments, Inc. CC2531 ZigBee Bus 003 Device 031: ID 0451:16a8 Texas Instruments, Inc. CC2531 ZigBee Still, whsniff gives a "ERROR: No working device found." /usr/local/bin/whsniff -c 20 ERROR: No working device found. How can I fix this?