Latte Dock -> Configure System Tray -> Entries -> System Services -> Clipboard is "Show when relevant". Change to "Always hidden" or "Disabled", "OK" or "Apply", don't work. Same when "Log out" or "Restart". "Show when relevant" never changing.

Operating System: KDE neon 5.22
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.85.0
Qt Version: 5.15.3
Kernel Version: 5.11.0-27-generic (64-bit)
Graphics Platform: X11