The Flatpak package should work in itself. It just shows a few messages regarding D-Bus access, for which we have not found any functional limitations so far.
What exactly the individual accesses to the system D-Bus are used for is not yet known in detail.
(Forum Thread / GitHub Issue)
One functionality that is unfortunately missing under Linux is the tray icon. However, this is not supported by the client itself, so it makes no difference whether you download the Flatpak, a system package or the official TS6 client from the website (please add this for TS6 Linux 
).
(Forum Thread / GitHub Issue)
Further differences to the Windows client are currently unknown. However, with the necessary dependencies, packages for your own distribution as well as the official download and the Flatpak should work.
However, I noticed that opening the client directly as a Wayland window introduces some additional errors. If I am not mistaken, the client opens as an XWayland window under KDE by default. So maybe check if that isn’t installed correctly.
If it still doesn’t work properly after that, try running it in a console and post the log, that might help the team to fix bugs. The TeamSpeak client itself also writes its own logs.
