Why is the mouse movement not captured in the openGL program developed in Linux?

Question

I am currently moving my opengl codes I developed in Windows/Mac to Ubuntu. I don't know if my Ubuntu has a really slow performance, or if my code is wrong. When the render window is open, the camera system should read the mouse movement and change the yaw/pitch/fork of the camera, but it just reads the keyboard input, and not the mouse movement. I can only move around the camera with the keyboard.

Here are the basic codes regarding the mouse callback.

int main()
{
    // glfw: initialize and configure
    // ------------------------------
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

#ifdef __APPLE__
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
#endif

                                                         // glfw window creation
                                                         // --------------------
    GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", glfwGetPrimaryMonitor(), NULL);

    if (window == NULL)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
    glfwSetCursorPosCallback(window, mouse_callback);
    glfwSetScrollCallback(window, scroll_callback);

    // tell GLFW to capture our mouse
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
    ....
}

Here is the mouse_callback() function I send to glfwSetCursorPosCallback()

void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
    if (firstMouse)
    {
        lastX = xpos;
        lastY = ypos;
        firstMouse = false;
    }

    float xoffset = xpos - lastX;
    float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top

    lastX = xpos;
    lastY = ypos;

    camera.ProcessMouseMovement(xoffset, yoffset);
}

Is it my slow Ubuntu problem or the code problem? This code even works in Mac, which is considered a really similar OS with Linux. I'm currently using the glfw3 library.

---

Here is the code related to the input keyboard processing, which works really well. (Just in case)

Inside my render loop

while (!glfwWindowShouldClose(window))
    {
        // per-frame time logic
        // --------------------
        VISITED = new unsigned int[11]{ 0,0,0,0,0,0,0,0,0,0,0 };
        float currentFrame = glfwGetTime();
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;

        // input
        // -----
        processInput(window);

        //render
        .......
        glfwSwapBuffers(window);
        glfwPollEvents();
    } 

My processInput() function

void processInput(GLFWwindow *window)
{
    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);

    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
        camera.ProcessKeyboard(FORWARD, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
        camera.ProcessKeyboard(BACKWARD, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
        camera.ProcessKeyboard(LEFT, deltaTime);
    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
        camera.ProcessKeyboard(RIGHT, deltaTime);
}

---

EDIT

I tried std::cout << "callback called" <<std::endl in the mouse_callback() function. It is called, but only maximum 2 times in the whole program. It's either called once or twice only when the program starts. Maybe it is a bug of glfw in Ubuntu