Plucking Chest Feather?

[SunnyGreenCheek]

I’ve had my Green Cheek Conure, Sunny, for about 1 and a half years now. About two weeks ago I noticed a concerning change in her behavior. I noticed she’s been distancing herself from me and has started plucking her chest feathers out. Her appetite hasn’t changed and she’s been playing with stuff in her cage as usual. I even change her toys out regularly and give her a variety of foraging toys. I’ve attached a picture for reference. Any advice on the matter would be appreciated