@haeckerfelix
I had this exact problem about 5 years ago, but with a different chair. It's the cylinder (pressure change causes a slight static buildup/discharge, that's just physics) and my research found that (at least in my case) it wasn't the screen, but the connector. Specifically it was connected through a cheap passive HDMI to DVI adapter with poor shielding. If I used an all-in-one HDMI-DVI cable or a better quality adapter, it was just fine.

Hopefully this helps someone!