Turn on a multi-functional pressure cooker (such as Instant Pot(R)) and select Saute function. Heat olive oil and add chicken cubes; cook until golden, stirring constantly, about 3 minutes. Stir in chicken broth, brown sugar, soy sauce, carrot, garlic, ginger, and chili powder. Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 7 minutes. Allow 10 to 15 minutes for pressure to build.
Release pressure using the natural-release method according to manufacturer's instructions, about 10 minutes. Complete releasing pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid. Reselect Saute function.
Whisk cornstarch in 1/4 cup water until fully dissolved. Pour into the pot and stir to combine. Cook until sauce thickens, stirring gently, about 4 minutes. Sprinkle with sesame seeds before serving.