unfortunately Beyley's program also broken on my device

NewThread({
  while:
    DoRender();
})
MainThread{
  while:
    DoUpdate();
    DoEvents();
}

NewThread({
  while:
    DoRender();
})
MainThread{
  while:
    DoUpdate();
    DoEvents();
}

bool isRunning = true;
IGLContext context;
void RenderLoop()
{
    context.MakeCurrent();
    context.SwapInterval(1); // for vsync
    var sw = new Stopwatch();
    while (isRunning)
    {
        var delta = sw.Elapsed.TotalSeconds;
        sw.Reset();
        // do rendering code
        context.SwapBuffers();
    }
}

void MainLoop()
{
    var window = Window.Create(WindowOptions.Default with { IsContextControlDisabled = true });
    window.Closing += () => isRunning = false;
    window.Load += () =>
    {
        context = window.GLContext;
        new Thread(RenderLoop).Start();
    }
    window.Run();
}

bool isRunning = true;
IGLContext context;
void RenderLoop()
{
    context.MakeCurrent();
    context.SwapInterval(1); // for vsync
    var sw = new Stopwatch();
    while (isRunning)
    {
        var delta = sw.Elapsed.TotalSeconds;
        sw.Reset();
        // do rendering code
        context.SwapBuffers();
    }
}

void MainLoop()
{
    var window = Window.Create(WindowOptions.Default with { IsContextControlDisabled = true });
    window.Closing += () => isRunning = false;
    window.Load += () =>
    {
        context = window.GLContext;
        new Thread(RenderLoop).Start();
    }
    window.Run();
}

    window.Load += () =>
    {
        context = window.GLContext;
+       context.Clear();
        new Thread(RenderLoop).Start();
    }

    window.Load += () =>
    {
        context = window.GLContext;
+       context.Clear();
        new Thread(RenderLoop).Start();
    }