VLC with telnet interface does not show GUI, consumes CPU

Question

I want to control the VLC player via telnet. What I want is to be able to set media, play it and pause it.

I found this command:

vlc.exe -I telnet --telnet-password test

It does work, I can connect but I see no GUI at all:

VLC media player 2.2.1 Terry Pratchett (Weatherwax)
                                                   Password:
Welcome, Master

The telnet CLI does not echo the commands, which is a bit annoying. Now I tried to add media:

add "D:\somepath\movie.mp4"

After that, the vlc.exe process starts eating 2 CPU cores.

When I type playlist I see:

> > +----[ Playlist - Undefined ]
| 2 - Playlist
|   5 - movie.mp4" [played 3935 times]
| 3 - Media Library
+----[ End of playlist ]

The play count is a bit suspicious, right? When I type stop, CPU usage drops to one full core.

So, what's wrong?