I recently purchased a vega 56 and I get terrible texture pop ins while playing forza horizon 3 and 4.
Game is unplayable for the most part as the road will disappear when I drive quickly. I updated everything to the latest and greatest and my build should be able to run the game smashing (it auto detects for ultra) I run FM7 fine but horizon just goes like poop
So, which version of drivers are you using? I believe this was corrected with 18.10.1 drivers... did you try a clean uninstall w/ DDU in safe mode?