The attached screenshot shows in the red circle the icon of the Device Notifier which should be as large as the Icon of the Moon next to it. I clicked left on this icon and the text "Geen apparaten beschikbaar" appeared in the Tray, which is the text I get when hoovering over the Device Notifier Icon. It stayed there, see Gee, the start in the blue ellips. Reproducible: Always
Created attachment 96894 [details] Screenshot with some extra ellipses
My issue seems very similar to the bug report. Every time i login, i get the "Show Hidden Icons" icon on the panel which is great but next to it there is always one of the "hidden" items. It disappears as soon as you click the "Show Hidden Icons". Its always a very very small "Device Notifier" icon. I will try get a spectacle shot of it and attach later as it didn't happen on this login session.
seen it sometimes one of the things hopefully solved by the systray rewrite
Created attachment 97260 [details] Image of small device notifier on panel Does go away from the panel when you press "Show Hidden Icons" and is then in the hidden icons list shown
Systemtray implementation is changed, this should be one of the problems fixed.
I'll check every log in for a week and see if it re-appears. I generally notice it without looking for it but I must admit, i've not noticed for a little while.