Why is this happening with skin modifier? here's a video of my woes https://youtu.be/ihAS3F3Zd_w
as i am trying to make feet that will have shoes on, so details aint a problem.
how can i arrange this ?

theres no node at the end, it just flops around. tried moving root .
i cannot just do it over again.

thanks 4 your help !.
I was able to recreate your issue by hiding the vertex at the end by selecting it and pressing H, then deleting a vertex in the middle. I have a sneaking suspicion this is what has happened. To resolve, when in edit mode, press ALT+H to un-hide any vertices or edges.