Using frameworks 5.26, and plasma-5.8.3 and krfb-16.04.3, there is not icon displayed in the systray when krfb is hidden. You can interact with the spot where the icon should be (ie. right click and get the krfb context menu) but the icon itself is missing.
Git commit b5d7a03d4231720d3ddb74d26e126decb353eea0 by andreas kainz. Committed on 04/01/2017 at 21:44. Pushed by andreask into branch 'master'. add krfb app icon A +161 -0 icons-dark/apps/48/krfb.svg A +161 -0 icons/apps/48/krfb.svg https://commits.kde.org/breeze-icons/b5d7a03d4231720d3ddb74d26e126decb353eea0