I recently submitted a modification request of the book https://en.numista.com/literature/volume.php?id=1908 adding related ruling authorities. They all worked except https://en.numista.com/catalogue/ruler.php?id=167. I wrote “Louis I”, and other forms (with English interface) but this king did not appear in the list. The next day, after validate my request, I tried again add this king. I wrote “Luis I” (with Spanish interface), with the same negative result. I asked to the referee @apuking and he can not add this king either.
We assume it is a bug. I do not know if this happens with another ruling authorities.