Summarising: refs from one child doc to a *later* child doc are BROKEN.
I created a similar trio of documents in 2.2.2 and the problem is not present, so this is a regression (at least with my installation on windows 7).
Andrew --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
test-child-1.lyx
Description: application/lyx
test-child-2.lyx
Description: application/lyx
test-master.lyx
Description: application/lyx