From this we can tell that FriendlyElec uses "80:34:28" as their vendor code. The remaining 3 digits compose the individual NIC address. Thanks for providing the script to work around the issue. It does what it needs to do, but it still raises the question as to why this is necessary. The FriendlyElec build does not require that we do this, so it would be great to have a base code fix. At some point I will try simply deleting the directory containing the script to see what happens ( - unless somebody else gets there first - 🙂 - ). For now, this script does what is needed ...
bracka@NanoPi-NEO3b:/etc/NetworkManager/system-connections$ hostnamectl
Static hostname: NanoPi-NEO3b
Icon name: computer
Machine ID: f86b967515a04b7aa4ee086b7ee8f50b
Boot ID: 7d724c0ff2a544f7959641728cacfe16
Operating System: Ubuntu 20.04.6 LTS
Kernel: Linux 5.15.78
Architecture: arm64
bracka@NanoPi-NEO3b:/etc/NetworkManager/system-connections$ ls -al
total 8
drwxr-xr-x 2 root root 4096 Nov 26 2021 .
drwxr-xr-x 7 root root 4096 Jun 13 20:55 ..