Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

When did this start happening and is it consistent across all ground textures, or only in specific places? It comes in and out, correct? So it flickers?

If reducing 'Glow' helped to an extent, have you tried reducing other settings? 'Anisotropic Filtering' and 'Parallax Occlusion' have some influence on ground textures, so you might want to try changing those and see what happens.

Try experimenting with different resolutions and settings to see what impacts it.

Do you have any other programs or overlays running while you are playing the game?

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!