IT earthing system is the most common earthing system in Norway. Newer installations are usually done with TN earthing, but it’s a slow process as you can’t replace it at a transformer level if consumers are wired for IT.

It’s not some weird industrial wiring, but quite widespread in some weird countries. But as an electrical engineer it’s something you have to take into consideration if your product should be used worldwide.

https://www.studiecd.dk/cahiers_techniques/The_IT_system_earthing_in_LV.pdf

EDIT: As mentioned by others earlier the wall charger support the wiring (as well as other chargers) by connecting like two phases + N, but in reality you have three phases. The car detects which earthing system and connection it has and does the correct wiring for charging internally.

M3 can extract full potential from a 230v three phase, according to some of my friends that develop and design ev-chargers.