Is the game using at least 90% of your card vram with the HD textures? I think the FSR is over sharpening the image in this game.I have uninstalled the game completely and reinstalled. It works better now in that HD textures are working more often, yet FPS tanks to single digits until I enable FSR and I do still get random texture loading issues. These are all indicitive of a VRAM limitation and not drivers.
Though having finally got it working and showing differences between HD on vs off, I think normal ultra with FSR looks alsmost as good as HD with FSR on. With FSR off you can see a bigger differece. With HD off and FSR on I get good FPS, sharp textures and no texture loading bugs.
So enable FSR, it adds some sharpening and looks great to the point where HD on is a case of pixel peeping to see differences. I recommend that anyone having texture issues need to verify the game is installed OK.