Hi,
I always say that breeding birds takes a lot of patience. You can set up everything by the book and still see no results. I’m not sure how old these birds are or how you are certain they are in fact male and female. Unless you had a blood test run on both birds, there is no way to know the gender of a lovebird unless it lays an egg. With absolutely no bonding taking place in over a year, my first thought is that you may have 2 same sex birds If their sex was confirmed by a blood test, then it’s hard to know why they are not interested in breeding. Breeding birds need a nutritionally balanced diet – a loose seed mix is not adequate. They also need chopped veggies and fruits, dark leafy greens, cooked eggs and multi grain bread. They need a large cage with the nest box affixed to the outside as high as possible. They also need a lot of privacy. If they were young when you put them together, they are just now old enough to breed so you may see some progress soon. All you can do is wait and see. Some birds are simply not good breeders. But hopefully your pair will soon show some interest.
Thank you for asking Lafeber,
Brenda