SUMMARY
When a create a bond via CLI with two or more NIC, i cannot see anithing in plasma SYSTEM SETTINGS -> NETWORK (no ETH1/ETH2 or BOND0). And no one monitor on Plasma is working. 
Instead in CLI mode the monitor on bond 0 work flawlessy.


STEPS TO REPRODUCE
1. Install at least two NIC bond via NETPLAN CLI;
2. Try to see config in Plasma System Settings -> Network;
3. Try a network monitor widget in Plasma GUI.

OBSERVED RESULT
Cannot see any result in GUI Plasma network monitor;


EXPECTED RESULT
Some result about traffic on Bond NIC in Graphic widget


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 5.13.0.19
(available in About System)
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 
Qt Version: 5.15.2

ADDITIONAL INFORMATION
This is my Netplan file:

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: networkd
  ethernets:
    enp1s0:
      dhcp4: false
    enp8s0:
      dhcp4: false
  bonds:
    bond0:
      interfaces:
      - enp1s0
      - enp8s0
      addresses:
      - 192.168.10.10/24
      routes:
      - to: default
        via: 192.168.10.254
      dhcp4: false
      parameters:
        mode: balance-alb
        mii-monitor-interval: 100
      nameservers:
        addresses: 
        - 192.168.10.253