Why is this keep happening?

I'm new at this and is the first time doing bottoms, I did the mesh in marvelous designer and followed the steps on blender but the steps that i follow were for doing a top, i haven't found one specifically for bottoms.
imgur.com/3fJ0lZK
imgur.com/RozUj7M
it works and all, but has this issue 
imgur.com/a/VZgzYJ
i already did 3 times the whole process the mapping and all but i have no idea what's going on