Outlinks query when tracking multiple sites

We are currently using the same container across 3 sites. We’ve noticed that those sites are being included in the outlink sites reported in the dashboard.

What’s the best way to prevent this from happening? Looking through the site it looks like there is an option that can be ticked when creating the tracking code. But as we have implemented the code already without 'In outlinks report, hide clicks to known alias URLs…" box ticked, is there another fix without having to change the tracking code and re-implement?

Thanks in advance