might be the rings

first things first though

how much did you torque the pan bolts to?
i think they're only supposed to around 8-9 ftlbs

and like someone already said... the oil pan mating surface not being completely flat can cause an issue aswell

i went through 3 oil pan gaskets before i realised there was a raised section in the area of where it was blowing out... i took a hammer to it and flattened it out and have been good for 2 months now