I am encountering a screen tear issue using OpenGL and WinApi. I am doing a ray marching demo (rendering just 2 triangles and ray marching and shading terrain in fragment shader). Rendering with GTX 860M, the app does not have an issue with staying at 60 FPS (at least at lower resolution). A screen tearing is present however (and this was rendered at especially low resolution to make sure this has nothing to do with the complexity of the fragment shader code):

Where I am at:

I am creating the OpenGL context using the recommended settings (https://www.opengl.org/wiki/Creating_an_OpenGL_Context_%28WGL%29).

I have tried manually turning VSync on using (wglSwapIntervalEXT(1)), although that should be the default behavior.

I have tried placing glFinish before the SwapBuffers call, i.e.:

while (isRunning)
{
	ProcessMessages(window, &context);
        App::Update(&context);
	glFinish();
	SwapBuffers(windowHandle);
}

I have tried setting VSync to "Always on" in the Nvidia control panel. I have also tried setting Maximum pre-rendered frames to 1.

None of these things have helped. Does anyone have any ideas? I have also tried running the app on a friend's PC (GTX 960) and the tearing was present there as well. Thanks.