There was a post about similar issue and it ended up being a problem with the model itself, as far as i can remember. Have you tried importing another mesh of the same size? Also try importing without triangulating and see if it changes anything.
There was a post about similar issue and it ended up being a problem with the model itself, as far as i can remember. Have you tried importing another mesh of the same size? Also try importing without triangulating and see if it changes anything.