MK5 jetta

I’m wondering if someone could help me diagnose a problem I’m having with my 06 Jetta tdi. It always starts fine right away but as soon as it gets up to normal operating temps of 190 degrees and you shut it off. It will start right up but die immediately. I was thinking it could possibly a temp sensor even though I replaced it already with a new one. Or could it be an issue with the immobilizer system?

Get it scanned. Post logs of fuel temp, air temp when at alleged coolant temp.
If the problem is the immo, a code will be stored too.