Use OnlineMapsMarkerBase.enabled.
http://infinity-code.com/doxygen/online … aac7ed8d01

protected bool visible
    {
        get { return _visible; }
        set
        {
            _visible = value;

            if (_visible && _showMarker)
            {
                instance.SetActive(true);
            }
            else if(_visible && !_showMarker)
            {
                instance.SetActive(false);
            }
            else if(!_visible)
            {
                instance.SetActive(false);
            }
        }
    }

    /// <summary>
    /// Adds control over the visibility of a marker without affecting the "_visible" logic
    /// that is in place.
    /// </summary>
    public bool ShowMarker
    {
        get
        {
            return _showMarker;
        }
        set
        {
            _showMarker = value;

            if(_visible && _showMarker)
            {
                instance.SetActive(_showMarker);
            }
            else if(!_showMarker)
            {
                instance.SetActive(false);
            }
        }
    }

The visible property, which was previously public, is now private. This makes sense, as it looks like the tool is using this to hide or show the marker based on if it is offscreen and such.

The issue is that the visible property sets the gameobject either active or inactive based on this, which means that the marker's gameobject can't be set to inactive (outside of the OnlineMaps code) to hide it either, because the visible property will change this on Update.

There should be some other property or logic that controls if the marker should be shown in general.