Solaar and onboard are showing twice in the tray-bar after upgrading to Debian 12

After upgrading Debian11/KDE to Debian 12, Solaar (for Bluetooth input devices) and onboard (for a virtual touchscreen keyboard) is showing twice in the tray-bar. I checked with the process manager and there only is one process for each of those. **Why are they showing twice, and how to prevent that?** No other are shown twice there. The context menu can be shown for both tray icons of Solaar. The second tray-icon for onboard looks slightly different from the other. When I click on the latter only a context menu is shown, when I click on the first the onboard keyboard is shown so these are definitely different. It may have to do with Plasma tray icon settings files (which should not be screwed up by updating). The four icons look like this in the tray: The second Solaar icon is on the most right of icons in the traybar, right of the network-manager icon. If I quit either application and restart it, only one icon is shown. I used X11 before and after the upgrade. When I switch to Wayland, the Onboard keyboard does show after login but, unlike with X11, it does not show in the tray (Solaar is in the tray with one icon) once I close that keyboard. **Update**: The issue still exists. All packages are up-to-date (Plasma 5.27.5). I made sure there is only one entry for each in /etc/xdg/autostart (make sure the one that remains has "KDE" in OnlyShowIn) and no extra entry in ~/.config/autostart. Both only show once in the processes (underneath branch systemd->systemd). It is strange that on another computer with Deb12/KDE, there is no icon for Solaar (also underneath systemd->systemd) even though it is running with one entry for it in /etc/xdg/autostart where both have Exec=solaar --window=hide and StartupNotify=true. When disconnecting the bluetooth receiver no icon is shown anymore and when reconnecting two icons are shown again. **At another nearly identical Deb12 machine no icon for Solaar is in the tray bar** (Plasma System Tray) except for a short time after connecting the receiver. Maybe there is another way to get info about things showing up in the traybar. A solution to this problem could also be useful for the disappearing tray icon for veracrypt where its GUI can't be opened again due to error "VeraCrypt is already running".