previous parent validation scope not working as per design/understanding

Summary:

i have a hierarchy, which has INACTIVE NODE and REVAL NODE as parents, there are multiple parents within those two as well. This hierarchy allows duplicate node.

i wanted to build a validation such that no one can move between INACTIVE and REVAL, (but can insert) but they are allowed to move within these two for sure.
when i use Previous parent as scope and say if node.parent = INACTIVE (Considering it will fetch the previous parent) and trigger is move, then it should through an error. but the validation does not seem to work at all.

and since i want to let move within the top nodes parents, so i cannot remove move action altogether. please help.