Hello!

In short, the application changes what it calls the window:

• While loading it calls itself "com.yubico.yubioath"
• but when the main window opens it seems to be called "authenticator".

This means that the application only matches its .desktop file (that provides the icon) during startup.
Since the main windows matches no .desktop file, it just gets a generic icon depending on if running x11 or wayland.

Expected behaviour is that the application does not change its name, such that only one entry is created in the taskbar, rather than one for the loading and one when its launched.

See this issue reported to flatpak, where I previously uploaded a short video showing the issue: flathub/com.yubico.yubioath#62 (comment)