(Posting this for future reference.)
Since installing linux headers 6.11.0-17-generic on Ubuntu
the network error "Cable unplugged" appears --
in Ubuntu Settings > Network > Wired -- when waking from
system suspend.
sudo systemctl restart NetworkManager does not make the problem
go away; a reboot does but that's rather tiresome.
Ubuntu Settings > System > About says,
- Operating System: Ubuntu 24.04.2 LTS
- Hardware Model: ASUSTeK COMPUTER INC. NUC14RVK-B
- Processor: Intel® Core™ Ultra 5 125H × 18
- Firmware: RVMTL357.0038.2024.0115.1528