CRT out on LePotato with Lakka

Hello,
I’ve recently bougth a LePotato, and i needed to display the video on a device that only support CRT input. I tried buying a converter:

After plugging it in the video was displayed, but in a green tone (instead of the blue menu of lakka). I tried changing the cables and all, and the only improvement i got was that the video turned violet.

Is it a problem caused by the converter or it’s about the configuration?
Thanks in advance

UPDATE

I’ve discovered that if I plug it into a normal monitor, then I unplug it, and pug in the converter it works everytime (WTF?)