When switching desktops with the function keys, Ctrl-F[X] The event seems to go unclaimed and the 'F' key also appears to be sent to the currently active application resulting in unexpected key events. seen in kubuntu 16.04 [ Apologies if this is a duplicate, I have struggled to formulate the appropriate search terms ]
Sorry to bother you. this is not a KDE problem, but something in SDL2. I just happened to notice the issue in two applications