Late to the party, discovering this thread…
Could be the bug I already saw from memory pre-SU5, even from the beginning, but from time to time it was fixed by itself weirdly, when moving the external camera around the plane and going back and forth to cockpit camera. It was during my test scene at Courchevel, when appearing on the tarmac the white line right below was always destructed (no anisotropic) even with my Texture at ULTRA, Texture Synthesis at ULTRA and the one I can remember its name at max (“texture supersampling”, I guess in English at 8x8 or 6x6, the max). I never forced or touched this setting in NCP.
Good find!
This one and the fact it seems settings are not correctly saved from “SU5 the First”
prevent me to fly. I know it’s stupid but I guess I want those ones to be fixed before trying again the Sim (and here the heat prevent me to put the VR headset, more than 30 degrees in the room 
).