
This seems to only happen from flatpak installs. When the flatpak app is run, the app spawns twice, one icon in plank with the app ID and one icon with the app name.
Even after closing the application, the one process with the app name sticks around for a couple of seconds and then closes by itself. Was unfortunately not able to figure out why this happens yet. The screenshot above demos whats going on.
I've created a sample repo for debugging this, its up here: https://github.com/BharatKalluri/double-icon-flatpak-bug