I have this issue too was going to send my graphics card back but everyone is saying it’s the driver . Do you think buying it on steam will help ?
I registered to report that this issue also is confirmed on two identical Vega 64 LC.
I hope that this gets fixed soon. I love Sea of Thieves and I play it a lot, but sometimes this glitch is near seizure inducing as black bars flash across the screen. It's a really annoying issue that got introduced with a driver update. Otherwise, my Vega 64's are performing flawlessly in all applications.
Here are a couple of screenshots: