API to control the sequence of series drawn in chartView when OpenGL is set

When a chartView has multiple series, they are drawn in order of their declaration. But when OpenGL is set to true, this order becomes random.
Please refer to the attached sample, where 2 series, green and purple have same points, meaning one overlaps other. But when OpenGL is on, sometimes green overlaps purple and sometimes purple overlaps green.
Ideally, these should be painted in order of their declaration.