Not sure if I'm doing the thinks correctly but,
I've create a main project and also create a set of sub-projects, when i create a new version/backlog in the main project i configure it to be at left or right side, when I go to a sub-project a can only see the versions configured for left side, if i want to see the right side ones i had to go to each version and change the side from left to right (i think when the version is inherited it must keep the side configuration made in the main project)

not sure if its a bug or its the expected behavior, if its the expected maybe this can turn into a new feature because go each of sub-projects and each of inherited versions/backlogs and reconfigure them its a waste of time.