Enabling Freesync on Sea of Thieves causes massive stutter, performance decrease (from 75fps to 55fps), and display flickering. My display fps counter shows fast switches between 40 and 144fps despite the game rendering at around 60fps.
Freesync works correctly on other games on the same system, such as overwatch.
GPU: 380X 4GB
Display: Asus MG278Q
Drivers: 18.6.1 beta