How to enable connector line jumps

I have a domain model, which when unions intersect, looks like this:

What I want to do is that, when two lines intersect, that one pass over the other, like the following:

Supposedly this should be done by the Enterprise by default, but it doesn't.

any ideas?

Go to Start | Desktop | Preferences | Diagram and set the option Enable Connector line jumps _{(valid for version 15.1)}