I'm new to 3d-printing so I prefer using the standard settings of Cura.
Every print starts with a prime blob. I guess that's ok. But as soon as the prime blob is ready the print bed starts raising at the same time that the print head starts moving. That causes the print head (to be more precise: the bottom of the front fan) to hit the top of the prime blob. If the prime blob is PLA then it just flattens a bit but it stays on its place. But if it is PVA then the prime blob often fal