I am having issues with a rigid flex board and the Autorouter... I have both the standard and the advanced router. The standard router is routing tracks on the flex side of the board on non-flex layers as well as outside the of the flex outline. The advanced router cannot complete a single route. It routes every pin with a stub track to a via but apparently can't route any further on flex layers.
I can't imagine this is normal behavior... I also found that if I turn on 'avoid obstacle' for manual routing, traces i route manually fail to avoid anything...