SUMMARY
When setting up a Plasma style to fall back to the icon theme as per https://develop.kde.org/docs/plasma/theme/theme-details/#use-icons-from-icon-theme, all of the wireless network icons in the system tray applet turn into a static wifi icon with full bars.


STEPS TO REPRODUCE
1. Create a plasma style with a blank network.svg icon to make Plasma fall back to the icon theme. (see https://develop.kde.org/docs/plasma/theme/theme-details/#use-icons-from-icon-theme)
2. Switch to the plasma style.
3. You may have to restart plasma shell for it to notice and use the icon theme.

OBSERVED RESULT
The network applet fails to report the connection type and strength.

EXPECTED RESULT
The network applet successfully reporting the connection type and strength.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Previously discussed here: https://bugs.kde.org/show_bug.cgi?id=459852
This happens because Breeze is missing the correct icons for the network strength and type and ends up falling back to network-wireless (in the case of a wireless connection) for everything. At least the following icons are needed:
network-wireless-0
network-wireless-0-locked
network-wireless-20
network-wireless-20-locked
network-wireless-40
network-wireless-40-locked
network-wireless-60
network-wireless-60-locked
network-wireless-80
network-wireless-80-locked
network-wireless-100
network-wireless-100-locked
network-wireless-off
network-wireless-on
There are probably more icons needed for wired and mobile connections, but I don't have any of those, so I can't check.