When resuming from a locked acreen in Debian stable (11) the tray icon is not visible in the GNOME tray provided by Topicons and its alternatives.
These forums are full of such complaints going back years. Why does it never get fixed???
The icon works fine in your direct competitors Dropbox and pCloud. I have Windows apps running using Wine where the icon works correctly.
There must be a hundred open source applications out there where the tray icon works correctly yet instead of copying them you continue to use your own broken implementation.