Updating Instances Increases Render Time with Motion Blur

I have a scene I’m working on that takes 40 seconds to render normally, but when I turn on motion blur on the physical camera, the render nearly gets stuck on “Updating Instances”. I let it go and after 30 minutes I gave up. I have the same objects in a different file with motion blur and I don’t have that problem. I’ve searched but haven’t found a solution. I restarted max and I have no displacement modifier in the scene.

I’m using Max 2019 with the vray_adv_62007_max2019_x64 nightly stable build.

Does anyone else have this issue?

Hello,

Mind if you send a scene sample to philip.shounev@chaos.com so we can investigate further what’s causing this slowdown?

Hi, thanks for posting. Have you tried to reset your render settings to default? Have you tried to merge your scene into a new empty scene?
Please test these steps and share the result.