https://bugs.winehq.org/show_bug.cgi?id=57370
--- Comment #11 from Ivo Ivanov logos128@gmail.com --- In addition to Xfce, tested Kde, Gnome, Cinnamon, Mate and Lxde.
Kde, Mate and Lxde work correctly with more than one systray icon.
Gnome shows only the systray icon of the last started app, although this does not seem to be related to the regression. After closing this app, it doesn't show the other Wine systray icons automatically. Showing the icon of the next Wine app can be forced through Layout Switcher or Show Apps. Anyway, this systray icon won't respond to mouse clicks, which seems to be caused by this regression. The provided patch actually fixes this exact problem. After applying the patch, Gnome works similarly to before the regression.
So, the aforementioned systray behavior for starting more than one apps in this bug report seems to be related to Xfce and Cinnamon. Cinnamon does some variation of the behavior, but it is still similar to Xfce.
However, There is another regression caused by a recent winex11 patch. The commit a319042690d277981d5b0eeefcc627feb198876b "winex11: Skip faking ConfigureNotify if state/config change is expected." causes Kde and Gnome systray icons to stop responding to mouse clicks. It also makes Xfce behavior exactly the same as the Cinnamon variation.