I would definitely test by hiding some possibly obvious culprits, namely the FP grass or trees.
It’s a guess, but maybe the grass or tree material in a view like that is causing it…two-sided/translucency/opacity etc.
You are out of RAM, badly so.
You notice during the LC because it’s the time when everything gets loaded/subdivided/displaced/scattered, that’s all.
I’d look into the scatter density of a few of the FP nodes, particularly those that scatter nodes smaller than the pixel you see: if the grass was 100 times denser, at this distance, you wouldn’t know, but still pay 100 times the price.
I’d also look into anything that you’re displacing, and needn’t do because of the viewing distance.
You may have to adjust per-camera, ofc, if they are more than one and look at different things from different points.
All good ideas, but I crashed MAX, hit render, and all went well. This will happen once or twice out of maybe a dozen times.

