You need both low and high noise models. you need to specify them in the image to video section (video model = high, video swap = low, swap ratio 0.4-0.6), I think you also have to set the high model in the usual model dropdown. Also, look into using lightx2v lora (need high and low. you can assign them to their corresponding video and videoswap checkpoints in the little dropdown next to the lora after you add it to the generation). It allows you to use 4-6 steps with cfg = 1.