[PLUGIN] Touch Display

Hi. Hope to be in the right place. I have just connected 7inch Sunfounder display connected through HDMI and USB. Everything fine with the plugin. The only stuff is that when the screen is off (as set in volumio) and becomes black, the backlight anyway is on. Is there any way to get it off? can anyone help? Apologize for the question.
thanks so much for help.
regards