Hi @max-f
Sound like there is a potential grounding issue taking place in your home or the location where this is being plugged into.
We recommend testing the outlet with a ground tester/outlet tester; something like this will suffice and should indicate if there is a grounding issue at happening. You can find these at most hardware stores, Amazon, etc.
Additionally, one of our engineers pointed out the following advice:
Our engineer: You should unplug everything, and unplug all devices from their hub/dock/device, so they are all isolated individually, and then plug each device in one at a time while checking the type-c port for sparks until they find which device is causing the sparks.