Cross-Domain Tracking issue

I have 11 domains that fall in a parent-child structure. 1 Main website with 10 subwebsites, each with it's own URL. So logically I have set-up the ga module to track multiple top-level domains.

The problem I have is that In the list of top-level domains (ga module settings) I've entered each of the 11 URL's correctly (1 per line). However when I check my google analytics account Acquisition>All referrals I notice that all the URL's are also seen as a referall website. My understanding was that in cross-domain tracking - which should automatically be set-up correctly by tracking multiple top-level domains - this should not happen. Am I doing something wrong here or is this a bug? I hope someone can point me in the right direction...