Buckets cut blurred parts of image

Hi,
I have problem with small objects with DoF (particles, grass, etc).
Some buckets didn’t render blurred part of image (please see attachment).

It is not related to Embree (as I thought).
Why this happens and how can I fix it?

P.S. V-Ray 3.40.03, 3ds Max 2016.

Hello,

Could you try upping the Min subdivs of the sampler to 2 or even 3 - that should help in such cases ?

Best regards,
Yavor