Most likely the battery protection circuit is kicking in and stopping them. You say you are not into sub-ohm coils, but not what the resistance you actually tried is. Your coil might also be shorting lowering the resistance below the threshold.
I have both those mods and use only IMR lithium ion batteries in them. I do sub-ohm so I bought MNKE 1600 mAh, 18650's rated for 20 A continuous discharge. The best IMO for you would be AW IMR 18490 or 18500. I am not up on 18500's so if there are other good options out there, someone please chime in. Best of luck with it!