Fonts displayed in a Knosole terminal in a KDE virtual desktop appears to be alternatively sharp and blurred. Initially they look sharp, but on any screen update (e.g. when Enter is pressed, or 'ls' command is given) they become alternatively blurred and sharpen again.

This problem has been encountered with NoMachine (free)  6.1.6 on Kubuntu, NoMachine client on Windows 10, VP8 encoding is used.

It occurs only when all these conditions are true:

- The NoMachine display quality to the maximum.

- 'Disable multi-pass display encoding' is selected.

- UDP is enabled (for connections by NX protocol)

As a temporary workaround, uncheck 'Disable multi-pass display encoding' in the 'Display settings' panel of the NoMachine menu run inside the session (ctrl+alt+0 to open the menu or click on the page peel in the upper right corner).

As an alternative, you may disable 'Use UDP communication for data traffic' in the Advanced connection settings for the NX protocol.