I've tried a number of different devices, Firesticks, Chromecast and I've always had an issue with something being out of sync.
I run a Yamaha RX-V585 receiver to a Sony XE9300 TV and with the Apple TV box, all apps are in sync.
With the Firestick I seem to remember it was Amazon Prime UHD content that had a lipsync issue. With the Chromecast I'm sure it was Netflix - I'll admit it has been a while since I used either.
Frustrating watching and I'm getting the sound, just milliseconds, before the movement - very off-putting in dialogue heavy sequences.