People Occlusion flickering on and off (ARPersonOcclusionTechnique - Mismatched timestamps)

I'm having an issue with the ARKit people occlusion stuff in my app. When I put my hand in view of the camera, the occlusion looks pretty good except there will be short flickers (probably just one frame) where the occlusion won't work. Then I noticed in Xcode that messages like this seem to be filling the console, roughly corresponding to the flicker in the frame.

The device I'm testing with is an iPhone 11 Pro Max and I've tried it with the fastest settings for both the depth and stencil occlusion buffers and without anything particularly heavy going on in my app. Anyone else running into this?

 

Oh also, I've tested the same thing on an iPad Pro 12.9" (2018) and I saw just one of the aforementioned console messages pop up but generally no perceivable flicker.

 

I faced the same problem.
how you solved it?