Slump Walk

Could you share some screenshots of the rigging hierarchy? Also the Head layer properties panel showings the "Attach To" value. Where is the attach point of the head set to? I normally draw the neck up behind the head (as part of the body) so the head has something to attach to. Its not clear yet whether the head is not attached in general, or whether it is attached but the tags are such that its pulling the head away from the body. E.g. where are the Neck and Head tags. If you look at the Walk behavior, and expand "Handles", it will show the points it is using from your puppet. It is then moving those points to move your puppet. Sometimes I have heard of weird behavior with Neck and Head on the same point - but just recently someone said they only got good results with Head and Neck on the same point!! So it can be a bit of trial an error for your artwork.

Need a bit more information about how your puppet is structured before can give any advice.