I'm neither a coder nor a developer, so please pardon any deviations from standard procedure to report issues.
Noi minimises to the system tray of Linux Mint 21.3 Cinnamon without issue. But if the main window is closed then it cannot be brought back up from the system tray. Left clicking the system tray icon of Noi just shows a ChatGPT pop-up sidebar which cannot be broken out of, to the main window. Right clicking that icon pops up a blank, narrow menu without any text at all. There seems to be nothing clickable even if trying blind clicking in that menu. I have to resort to killing it using the task killer.