Inconsistent systray Icons on Gnome

[Meincrakker]

I currently use "AppIndicator and KStatusNotifierItem Support" to show System Tray Icons on gnome.
When installing the app not with Flatpak (I tested the .rpm, .appimage and .tar.xz) the tray shows up correctly, with no black sqare background and the right click menu implements nicely with Gnome. But only the "open Deezer" and "close Deezer" buttons work on my end. The buttons not working has been reported in this bug.

When installing the app as a Flatpak the icon has a black background and the right click menu doesn't adapt to the system theme. But ALL the buttons do work. (It doesn't adapt theme in KDE either.) I think that this different menu results in this bug in which a new "correct style" window will be implemented.

[Meincrakker]

UPDATE:

I did now find out what dependency was making the difference.
If "kf6-kstatusnotifieritem" is installed (which I somehow did - it is not installed by default in fedora-gnome-workstation) the different theme shows up. I think this is because electron checks if this "kf6-kstatusnotifieritem" is installed and if not defaults to the "gtkstatusicon" - which is deprecated.
This is only a theory I got from the documentation.

Also by installing this dependency the middle buttons stop working. I am not at all qualified to find out why and how to fix it, but I will be running deezer using this, because there is a bug where the black box behind the deezer tray icon just stays in the top bar - which is very annoying.
But now should explain this bug.

PS:
The black box appears if you for example want to "show the desktop" using touchpad gestures, it only disappears if you logout and login again. In the picture I used the gesture, then the box appeared and then I left deezer, the black box staying behind