I've got the same GPU & CPU as you. I also have SAM enabled.
Do you have an HDR-capable monitor? If so, have you tried enabling or disabling HDR within Windows 10 itself?
Is your monitor using FreeSync? I would try overriding the game-specific settings to try "On", "Off", or "AMD Optimized" to see if that makes any difference.
Whether you have HDR or not, have you tried playing within a Borderless Window or Fullscreen?
What sort of resolution / framerate are you using? I upgraded to a single 49" monitor running at 5120x1440).
Hope that Helps!
Ryzen 7 5800X • Radeon RX 6900 XT • 64GB RAM