The ref-name this is about is "GC2020". If you do a text-search in the source, you will find that it is used quite often, (and that is not the problem). However, the position where its target is currently specified makes it so, that the reference is not carried over to Aesthetgender (starting from where I found the problem), hence there we get an error message instead of a link. I figure every of the Xenogenders listed would run into the same trouble if the Basic Information sections are copied the way it is for Aesthetgender, unless specs are copied in every instance(?), so I hesitate to do anything for now and ask for thoughts and ideas about this first.
Related: 1: On the Ethegender-page the problem seems to be solved, but it does not look pretty (two reference-markers instead of one, and at least one of them is obviously working for some reason). 2: Of the Xenogenders listed, some appear to link to another wiki-page, but five of them direct to the Xenogender-page itself. Should that stay this way (as a reminder to write something about them or something)?