changing the same relationship type of a relationship from A to B or vice versa does not work

If you tried to reverse an A or B relationship then it will not get saved .

Steps to replicate :

1- go to any contact page
2- open relationships tab
3- add a relationship as "Parent of" and choose another related contact.
4- after saving click the Edit button, edit the type and choose "Child of"
and check if it gets saved .
5- it will not get saved and it will stick to "Parent of"