Android 'Unable to add window -- token null is not for an application' exception only with TYPE_ACCESSIBILITY_OVERLAY

I'm trying to create an accessibility HUD that overlays with translucent colors the system.

I have a Service that calls my HUD class (which is another Service)

startService(new Intent(getApplicationContext(), HUD.class));

My HUD Service class:

    @Override
    public void onCreate() {
        super.onCreate();

        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        filter = new View(this); 
        float alpha = (float) 0.8; 
        filter.setAlpha(alpha);
        filter.setBackgroundColor(Color.RED);
        filter.getBackground().setAlpha(80); 

        WindowManager.LayoutParams params = new WindowManager.LayoutParams(
                -1, // Match parent
                -1, // Match parent
                WindowManager.LayoutParams.TYPE_ACCESSIBILITY_OVERLAY,
                WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE |
                        WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH |
                        WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
                PixelFormat.TRANSLUCENT); 

        params.gravity = Gravity.TOP;
        params.x = 0;
        params.y = 100;

        windowManager.addView(filter, params);
    }

This code however, only works if I change WindowManager.LayoutParams.TYPE_ACCESSIBILITY_OVERLAY to WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY, however that is not what I want. The error I receive is:

     Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?

I have tried changing the way I get the context as suggested in multiple links, from getApplicationContext() to MyActivity.this (for that I had moved my HUD Service class to an Activity for the sole purpose of getting the context in a different way. That still gave me the same crash and it disappears if I don't flag the window as an accessibility overlay.