Sorry, I should have written "Mesh Resolution", not Texture Resolution, which is what manuals says. The manual says "10 m/pixel or better", because it's not SURE that, if you set it to a better value, it will always cause spikes. It depends by other 3rd party meshes you have installed.
So, start with 10 m, and if you really need to set it higher, go up one notch until the problem reappears, so you know what the highest setting you can use.