I was using ranger file manager in konsole. I can't use the <ctrl-h> shortcut which is the ranger key binding to show hidden files. I can use other combination of ctrl command for ranger. I check shortcut in setting and Ctrl+h is unused in everywhere.
I test it with xterm terminal emulator. It is still unusable in xterm.
So it might not be specific to konsole, i don't know.
I use <ctrl+h> fine in tty with nothing but bare tty, no de, no wm.
I do not understand why KDE is suppressing <ctrl+h> in ranger in konsole.
I press <ctrl+h> in Firefox in which it trigger show history tab. In Firefox, it is fine. It bugged me.