If you are using KDE in the ThinLinc session, then you can get an issue where the keyboard from the client isn't always properly transferred. Issue was reported upstream here: https://github.com/TigerVNC/tigervnc/issues/1586 And fixed here: https://github.com/TigerVNC/tigervnc/commit/8d2739fa71eaf7a28d63ac62583e8087c66a5247 This also prevents server applications from modifying the clipboard in the background, which is probably a safer behaviour.