It's more than likely molten e-liquid spitting up from the atomizer. When I first started
vaping I would get these little 'shocks' until I read what they probably were on ECF.
If you want to prove to yourself beyond reasonable doubt, use a delrin, glass or wooden drip tip and see if you still get it. If so, it's liquid.
If you want to avoid it, you can use a longer drip tip, turn down your device or use a higher resistance coil. Depending on your topper, you could also put a small flavor wick on top of the wick that goes through the coil to reduce spitting liquid.
Now if it is really shocking you, well that's a different thing. I highly doubt it is, but I would stop using it and speak to the vendor for advice on returning it for testing. Maybe even talk directly to Innokin.