cold start problems i30 1.4crdk gdh

Hello together, I drive a Huyndai i30 1.4 CRDi built in 2012 from august with 90ps running power about 161tkm. Before I tried to find the solution about existing posts and other forums unfortunately without success. Therefore I opened a post. I have problems with cold start. I have to catch the car very long organs until it is on about 10-15 seconds. Once the is on and something has run it starts the rest of the day without any problems. After 3-4hd standing time at 5 degrees outside temperature di e problems again and it squirts whitishly like the sow. What was done error memory read out -no errors engine cleaner of LM inturned all glow plugs replaced. Inspection new diesel fuel filter new All fuses tested. Battery tested Has anyone an idea or even the problem and could eliminate it? Many greetings