New cam sensor - car won't start (Tucson 2006 diesel)

I own a 2006 Hyundai Tucson CRDi 2.0. Starting the engine has become slow recently, and the shop diagnosed it to a bad camshaft sensor. I bought a new one and replaced the old. With the new one in place, the car won’t even start. It sounds like it tries to start, but when releasing the key it dies out.

I think I did everything right; disconnected battery negative, disconnected old sensor, replaced and plugged the cables back in.

With the old sensor in place, the car starts (abit slowly after cranking for a bit).

Any ideas what might cause this? Might it be the ECU not recognizing the new sensor