Press the Sauté button on an Instant Pot® and allow to heat until the display reads Hot. Place the butter, carrots, celery, and onion in the pot. Sauté 3 Minutes until fragrant. Pour broth into the pot and scrape the bottom of the pot with a wooden spoon to remove any browned bits. Add chicken, salt, pepper, garlic powder, and thyme. Press the Cancel button.
Place the lid on the Instant Pot® and click into place to close. Press the Pressure Cook button and adjust the timer to 7 Minutes. When the timer beeps, quick-release the pressure until float valve drops. Unlock lid. When done, vegetables should be tender.
Add noodles to the pot while keeping the Keep Warm mode on. Let noodles cook uncovered 10 Minutes until tender, stirring occasionally. Serve warm.