My birds are definitely different...

[FinchLover&Breeder]

Hey guys it's me Nick again. Today I come to you with some questions, some tales, and also being tired. Here's why I'm tired:
As you guys know I am trying to breed my zebras again. For a while I had the proper type of nest for my finches put in the correct way in the cages. As I watched my one pair (Momma Bird and Jack Sparrow) the male would take the materials I provided to the nest and would put them in. In the meantime while he did that the female only wanted to spend the nights in the nest. He tried to woo her in his way (by preening her feathers to see if she was accepting or not) and she told him no in her own way. I figured they didn't like the nest. So I took that nest out and replaced it with the nest I had given them last year. The nest still had almost all of the materials that were in it last year (I cleaned the feces out and all lose materials that could prove dangerous) and after they calmed down I saw the female go into the nest and try to move stuff around. I was happy because I could see they both liked having their old nest back. Then around 7 am this morning I was awoken by the sounds of my birds. It turned out that the pair I gave the new nest to was breeding. So while I'm a little grumpy and tired I'm also happy because I know I'll have at least one clutch layed and hatched this year. So yea for that. Hopefully I get different mutations then last year from them and their clutch(es). Any guess what mutations I'm likely to get?

Now comes the questions. In my other large cage I have another pair I'm trying to breed. They are my Florida Silver (Pearl) and Fawn (Kiwi) couple. I know for a fact that Kiwi is of age and able to breed and lay eggs because while I had her with Jack Sparrow they apparently breed with each other because she layed 2 eggs (one of which was destroyed by someone else, not sure who). However while I have them with proper nest setup in the proper way I haven't seen or heard them breed once. As stated earlier I know Kiwi is ready and able but I have a feeling that Pearl might be the problem. Is there a chance that he isn't interested in breeding with Kiwi or is it possible that his mindset isn't mature yet and therefore he isn't mature enough to breed? Any knowledge on this will be greatly appreciated.

Sorry for the long post but figured I'd update y'all.