I first created this topic thinking there was a problem with fertility increasing refusal chances, but thanks to some other people sharing their experiences it's now known the problem is with holiday dragons when breeding with a new dragon during their respective seasons.
There seems to be a "hidden" refusal for many pairs of holiday x commons that are bred for the first time during holidays. Even though there is a 100% guaranteed chance at successful breeding during holidays, even w
As others have pointed out, this is far from a new issue. Even with the "recent" fertility changes (which happened back in 2016, so they've affected both the 2016–17 event season and the 2017–18 event season), fertility in general having no effect on holiday breeding, as well as successful holiday pairings potentially refusing outside of holiday breeding season have been the "norm" for years.
Despite this, it's definitely not an intuitive set of interactions, so the following change