The krdc & xfreerdp combination is terrible. I don't know which program is at fault (probably krdc), but it's not working well at all.
There's the occasional random disconnection to right-click rarely leading to disconnection to a case where xfreerdp asks for a password in the terminal but I don't see it in krdc.
The first & last are definitely long standing. The second is rare, but I think it got worse recently. All of these are frequent enough to annoy, but not frequent enough to make the combination useless, since I can reconnect.
I will be giving remmina a shot to see if it improves things, though I'd have rather used a Qt-based client as to match KDE better.
There's the occasional random disconnection to right-click rarely leading to disconnection to a case where xfreerdp asks for a password in the terminal but I don't see it in krdc.