Noisy Powertrain after Transmission Service

I have a 2015 Prius v with 142k miles on it. I first had the transmission fluid changed at 65k miles and then again at 140k. Both trans services were done at the dealership. After the most recent one, I noticed that my powertrain is noisier than it was previously. I can't tell if it's the engine or transmission, and the sound isn't what I'd call particularly unusual, except for being louder than normal. It only happens when driving and is more pronounced at higher speeds. I've had no problems shifting gears or with it slipping at all. Any ideas as to what this might be and how to correct it?