This one is a bit exoteric. Recently after updating my system ('apt upgrade' and 'snap refresh') the discord app started showing two icons on the system tray instead of one. It happens only after some time after opening it, and so far I think discord is working exactly the same. So its more of an visual annoyance than anything else. If I click on any of them and select "quit discord", the app will close and both icons will disappear. Then opening the app again will only show one icon for a while.
Im still trying to investigate what exactly triggers the second icon to appear. I usually only notice it when I leave my computer for a while, and then when I come back the second icon is there. Discord is only installed via snap.
Removing it ('snap remove discord') and installing again didnt work.
Im on Ubuntu 22.04.1 LTS.
Edit: I found that the trigger is having the monitors turn off (in the power settings, mine are set to turn off after 2 minutes of inactivity). When I come back and move my mouse to wake-up the monitors, the second icon is there.