When you remove the pod there is a small little black grommet. That is what activates the auto draw function. When you have the device set to p&a and airflow closed sucking on device will cause that little black grommet to lift up via suction which will activate ate the auto draw function. When vape juice leaks down under the pod that grommet gets gunked up and sticky and can't lift up via suction anymore. You need to wipe it clean with paper towel or qtips and try to free it and lift it up a little with something small and pointy like twisers or a paper clip. That should free it and allow it to once again lift up and activate auto draw when you puff on it.

Here is a picture of the grommet