Struggling with training programs

[Raadush 0]

Hi. I honestly dont know what is wrong or what am I donig wrong. I am no expert by any means on the game so that can be because my bad skill. I have created my team, I have my difficulty set up that way I am close to my teammate and racing at the level of teams according to performance table. Slightly slower than AlphaTauri, very close to Haas. But I nearly can't complete tire, fuel and ers programs. I have to pull off my absolute best lap to even keep delta in green and whenever I try to coast a little, or harvest, or ease the tires, I immidiately drop to red delta. So my best program results are at best -0,100 delta, with red-green-purple sliders just a notch above red. Why is that? In previous games I had very little problems to score purple at the same difficulty