Windows 10 1903 | Disconnected Remote Desktop Sessions cause heavy CPU load.

Its a display driver problem, Do gpedit.msc: Local Computer Policy Computer Configuration Administrative Templates Windows Components Remote Desktop Service Remote Desktop Session Host Remote Session Environment Use WDDM graphics display driver for Remote Desktop Connections to DISABLED Credits:

Remote desktop keymap problem

Do you have keymap problems connecting from linux to windows? Maybe rdesktop -k KEYMAP cannot find the keymap file it is searching for. Check /usr/share for rdesktop/keymaps and copy this stuff to ~/.rdesktop/keymaps/