Need ofxMultiGLFWWindow set to fullscreen help

Hi am using the great ofxMultiGLFWWindow add-on. I created 2 screens on my mac and it is working fine. But now i tried to set them to fullscreen. With an for loop i iterate trough the windows pointer and then set them to fullscreen via ofSetFullscreen(true). But only the first one is going in fullscreen mode, the secondary stays normal on his init values.

Code
for (int i = 0; i < numScreens; i++)
{
file.pushTag(“screen”,i);
int posX = file.getValue(“posX”, 0);
int posY = file.getValue(“posY”, 0);
int sizeX = file.getValue(“sizeX”, 100);
int sizeY = file.getValue(“sizeY”, 100);
glfw->setWindow(windows->at(i));
glfw->initializeWindow();
ofSetWindowPosition(posX, posY);
ofSetWindowShape(sizeX, sizeY);
ofSetWindowTitle(“window_” + ofToString(i));
ofSetFullscreen(true);
file.popTag();
}

any help would be nice.

Solved, RTFM.
I forgot to set the setMultiDisplayFullscreen.