Birds are creatures of love, and when you don’t give them the time and devotion that they need, they can turn somewhat hostile, trying to remind you about their needs.
Spend more time with your bird, let it out of the cage more, and give it more of its favorite treats and food. What I would suggest is to make a fixed schedule of playtime with your bird.
Pet birds can sometimes get jealous; it is not unheard of. There are many reasons for it – but most specifically, if it is because you have introduced a new bird in the cage or environment.
The first thing to do is to reassure the pet that you are still very much its friend. Shower your earlier pet with love and attention.