Angel
Hi. Yes and no. Parent field has not data, it is a calculation, so ww28 has not Time Machine... the changes occur into the children component ww27. The same happens into the thesaurus: Dependent of hierarchy36 has not data, and the changes occur into the Children component hierarchy49.
So, Yes, is normal and correct. Only children fields has data and TimeMachine, Parent is an operational component that save into children... if you want trace the changes you need to see the children TimeMachine.
And yes... we need to remove the TimeMachine tool for the component_relation_parent, it's confusing.
Best