Linux capabilities are removed from the node and python3 executables when running the Gateway on NFS instead of an SD card.
Generally, I’ve been very happy since I migrated my RPi 4 to run from NFS and I don’t worry about too many writes melting down the SD card.
It may be possible to configure NFS to support capabilities for executables but I have not researched this yet. In the meantime, I added a systemd drop-in to the mozilla-iot-gateway.service to mitigate this issue. The dropin contains the two lines
[Service]
AmbientCapabilities=cap_net_raw