If you save draft while you are in New Editor then html will be stripped off before saving, if you save draft while in Classic Editor then html and all formats stays, when you open draft again, it might open in New editor but you can quickly switch to classic editor to see html and continue editing/publishing there. We will see what else we can do to improve it. I would say, give new editor a chance, you might enjoy it more once you get used to it (no need to learn html/markdown codes anymore).