Vulkan is completely broken with heightfields it seems. It occurs with the latest production build(20.5.487) and even with the latest daily build(20.5.510).

Is anyone else experiencing this? Im worried about a deeper issue on my end.

I submitted a bug report and Im using OpenGL for now.

I am seeing the exact same behavior as the OP. Eventually Houdini will crash. Thanks for the bug find on this SadowickProduction.
I think this is the reason I am crashing a lot in heightfields lately. Thanks again for the find. Hopefully SideFX can fix this quickly. Did you open a ticket with them?

I am using:
Windows 11 (10.0.26100.3194)
AMD Threadripper 7980x with 128 Gb Ram
Nvidia RTX 4090 (572.42)
Houdini 20.5.487

For anyone else experiencing this try using Houdini 20.5.445 + Nvidia driver 566.36. That stopped the crashes for me.

And yes I did submit a ticket and Im giving them more and more info.