In a small bowl, whisk the soy sauce, pineapple juice, brown sugar, garlic powder, ginger, rice vinegar and sesame oil together until well combined
Pour the olive oil into the inner pot, and place the chicken in the pot.
Pour the teriyaki sauce over the chicken, and place lid on the Instant Pot
Turn vent to Sealing position, and hit PRESSURE COOK for 10 minutes. Pot will take a few minutes to reach pressure and start cooking
When pot beeps, allow a natural release. When pin drops, hit CANCEL to turn pot off, remove lid, then remove chicken to a plate, and slice. Cover with foil to keep warm.
Mix cornstarch and soy sauce (or water) together in a small bowl. Hit SAUTE, and when sauce starts to bubble, stir in the cornstarch slurry and allow to cook until it starts to thicken.
Hit CANCEL, add chicken back to pot, and stir. Serve immediately.