1) I installed TDE on my system, while KDE is already installed (and
fed up with it, I'm searching for an alternative).
Besides that (just for being sure), I installed EXE Linux (which is
Devuan with TDE, with a bit altered graphic theme), and I had the very
same issue.
2) I did the minimal installation.
3) Indeed I installed Wicd's GTK interface. Tray icon appears in KDE,
but not in TDE.
G.