GLFW_DECORATED for the secondary monitor makes GLFW_SAMPLES for the thirdly monitor ineffective

support
1

the marked line A in the following codes makes the the marked line B ineffective, i.e., the antialiasing doesn’t work for the third monitor. What causes this problem?

int MakeContexForSubjectMonitors(int DisplayToWhom) 
// DisplayToWhom: SUBJECT1 , SUBJECT2
{
	BOOL doubleBuffer =  TRUE;
	if (MonitorNum == 3) //we have 3 monitors, the last 2 were shown to 2 subjects 
	{
		if (DisplayToWhom == SUBJECT1)
		{
			glfwWindowHint(GLFW_RED_BITS, moninfo[2].redbits); // moninfo: monitor information
			glfwWindowHint(GLFW_GREEN_BITS, moninfo[2].bluebits);
			glfwWindowHint(GLFW_BLUE_BITS, moninfo[2].greenbits);
			glfwWindowHint(GLFW_REFRESH_RATE, moninfo[2].refrate);
			glfwWindowHint(GLFW_DOUBLEBUFFER, doubleBuffer);
			glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
			glfwWindowHint(GLFW_DECORATED, GLFW_FALSE);//**********marked line A
			glfwWindowHint(GLFW_SAMPLES, 4);
			glfwWindowHint(GLFW_FOCUSED, GLFW_FALSE); 
			glfwWindowHint(GLFW_FLOATING, GLFW_TRUE);
			glfwWindowHint(GLFW_CENTER_CURSOR, GLFW_FALSE);
			glfwWindowHint(GLFW_AUTO_ICONIFY, GLFW_FALSE);
			
				window1 = glfwCreateWindow(moninfo[2].width_pixel, moninfo[2].height_pixel, "To Subject1", NULL, NULL);
				glfwSetWindowPos(window1, moninfo[2].virtualPos[0], moninfo[2].virtualPos[1]);
		else
		{
			glfwWindowHint(GLFW_RED_BITS, moninfo[3].redbits);
			glfwWindowHint(GLFW_GREEN_BITS, moninfo[3].bluebits);
			glfwWindowHint(GLFW_BLUE_BITS, moninfo[3].greenbits);
			glfwWindowHint(GLFW_REFRESH_RATE, moninfo[3].refrate);
			glfwWindowHint(GLFW_DOUBLEBUFFER, doubleBuffer);
			glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
			glfwWindowHint(GLFW_DECORATED, GLFW_FALSE);
			glfwWindowHint(GLFW_SAMPLES, 4);//********marked line B
			glfwWindowHint(GLFW_FOCUSED, GLFW_FALSE); 
			glfwWindowHint(GLFW_FLOATING, GLFW_TRUE);
			glfwWindowHint(GLFW_CENTER_CURSOR, GLFW_FALSE);
			glfwWindowHint(GLFW_AUTO_ICONIFY, GLFW_FALSE);
			window2 = glfwCreateWindow(moninfo[3].width_pixel, moninfo[3].height_pixel, "To Subject2", NULL, NULL);
			glfwSetWindowPos(window2, moninfo[3].virtualPos[0], moninfo[3].virtualPos[1]);
		}
	}
	

	if (DisplayToWhom == SUBJECT1)
	{
		glfwMakeContextCurrent(window1);
	}
	else
		glfwMakeContextCurrent(window2);
	
	glewExperimental = true;
	int initcode = glewInit();
	
	if (DisplayToWhom == SUBJECT1)
	{
		glViewport(0, 0, Monitor2_HorizontalResolution, Monitor2_VerticalResolution);
	}
	else
	{
		glViewport(0, 0, Monitor3_HorizontalResolution, Monitor3_VerticalResolution);
	}
	

	glEnable(GL_MULTISAMPLE);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_CULL_FACE);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); 
	glEnable(GL_BLEND);
	glEnable(GL_PROGRAM_POINT_SIZE);

	//simple demonstration
	glClearColor(0.0, 0.0, 0.0, 1.0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glBegin(GL_TRIANGLES);
	glVertex2f(0, 0);
	glVertex2f(0.3, 0.3);
	glVertex2f(0.3*tan(5.0 * PI / 180.0), 1);
	glEnd();
	if (DisplayToWhom == SUBJECT1)
		glfwSwapBuffers(window1);
	else
		glfwSwapBuffers(window2);

	return 1;
}