qemu with whpx acceleration crashes with vmx=on

Under Windows 10, qemu crashes when using whpx acceleration and the vmx=on option.  The reported error is
  qemu-system-x86_64.exe: WHPX: Unexpected VP exit code 4
Before the error, it reports
  Windows Hypervisor Platform accelerator is operational

The command line is the following:
  "C:\Program Files\qemu\qemu-system-x86_64.exe" -accel whpx -cpu qemu64,vmx=on
It crashes with any model of CPU as long as the "vmx=on" option is added.  Without this option it runs fine (but no nested virtualization).

My processor is an Intel i7-10510U, and I am running Windows 10 2004 (build 19041.572).