Hi @andrakar,
it is the expected behaviour for a command-line application to “block the command-line” when running. Most other Linux command-line applications for audio work in the same way.
As @NeonSilicon suggested, you can add & to launch SUSHI in the background, or you can open another SSH session, or even better you can use a terminal multiplexer like tmux that we included in the distro.
Which plugin are you trying to run and connect to a MIDI Keyboard? There is an issue with the MDA JX10 VST2 version in this build.
Check also this reply on another thread to see how to debug incoming MIDI in SUSHI.