Bruce is having issues with audio sync on his TV and home theater/DVD player. Leo says that sync is often built-in and should be in the settings for the device. Bruce gave up on his FireStick. Leo says that a lot of people have. There are some tricks like turning off encoding (or on). Look at the TV settings as well. Maybe a better HDMI cable would help.
From the chatroom - check the manual for AV Sync. https://www.sony.com/electronics/support/articles/00012347