The current bundled electron version has a bug that prevents tray icons from working on ubuntu/wayland. A fix has been deployed upstream and should be included in the next electron release - see electron pr #52952
Until then downgrading to the 1.13.4 installer negates the problem.
See the post “Linux tray icon is a dead placeholder — Obsidian 1.13.7 bundles Electron 43.3.0, fixed upstream in 43.4.1” in the bug graveyard for further information.