CIEL: Duplicate names in 1.11.x for Eparinn & Gratel in 'ht' locale

Thanks @judy, for the summary of findings! Can you please explain it to me like I’m dumb, and I need detailed explanation?

I see that one problem is that the UI is displaying things incorrectly when there is no preferred/fully-specified name.

But besides that, what is the thing that is going wrong in code and we need to fix?