Icon inconsistency across Xfce (Issue with all icon themes)
Window cycling (alt + tab) and Window Buttons do not use the correct icons for many third party applications like kitty, keepassxc, steam, calibre, mpv, obs studio, nvidia-settings, pidgin, gnome-calculator and many others. Also, most apps that had their tray icon changed by hardcode-tray end up displaying their tray icon in Window Buttons. Launchers and Whisker Menu always display the correct icon.
I have this issue in many Xfce installations (Arch, Fedora and Debian). I think it would be better to make Window Buttons and Window Cycling display the same icons as launchers and Whisker Menu do.