Starting issue?

"I have a 2006 S-Max 1.8 TDCI (QYWA). The turbo, high-pressure pump, MAP sensor, injectors, new battery, IAT sensor, glow plugs, upper timing belt, crankshaft position sensor, and camshaft sensor have all been replaced. The problem is that the starting behavior is unpredictable, regardless of the outside temperature. For example, after replacing the fuel filter, it started immediately, but there are times when it only starts after several attempts. Sometimes, it starts and then immediately stalls. If it starts, I let it run for a few minutes or drive a few kilometers, then shut it off, and it still takes two attempts to start again. The EGR is blanked off. When it wasn't blanked off, I monitored the EGR signal with live data, and there was a point at 1700-1800 RPM where the signal went above 100%, causing the engine to jerk, which is why I decided to blank off the EGR. Since then, the jerking issue is gone, but the starting difficulty remains. I don't know what else to check. Thank you for your help."