MBP Retina, 13-inch, Early 2015, graphic card issues

Dear alll,

I have a new MBP retina display (Retina, 13-inch, Early 2015), and when I start the Macbook connected to a HDMI display (LG 24MP5HQ -P), the display of the Macbook distorting video like a rainbow. After the first instance all works fine in booth screens.

There is a problem with the graphic card, or hdmi port? or this situation is normal?

Please can I help me?, in the past I had a horrible experience with dead graphic cards on Macbook Pro after two half a year.

Best Regards,