Any idea why and how to fix it? I tried tweaking many world space settings.

WhiteOak1 also works in new interior cells (tried it just as a test)

Scaling it down makes it work, weirdly enough... the whiteoak01 in the wasteland isn't scaled down though
0.4 works but 0.5 doesn't.

This problem is more important than it looks because WhiteOak01 is one of the few healthy tree models in the game. All the other trees work fine in the same circumstances.

Any ideas please?