Still not breeding, they eat the hay bales, get hearts, nuzzle, I heard a ping sound so they seem to have dropped XP, but no baby.
And then they don't take any more hay for a while.
Oh well, I managed to get a Respiration III helmet, even if only iron (and then I found a leather Respiration III helmet as a spare) so I've been out raiding ship wreaks and now have the full 15 bookshelves for my enchanting table so I don't need any more leather.
Breeding the traders llama with a llama I found normally, resulted in baby. Was weird though, maybe I just don’t pay attention to my llamas when I breed them, but the traders llama walked away and the other llama followed.