The ACVP Proxy potentially runs for an extended period of time. The Apple macOS power nap interferes with the ACVP Proxy. The per-application nap functionality is already disabled. But the system-global power nap is not disabled.
If the power nap is active, the ACVP Proxy stalls. Thus, you must disable the power nap if you want to execute the ACVP Proxy without monitoring and preventing the power nap to kick in.
To disable the power nap, do the following:
1. Open the system settings
2. Open "Energy Saver"
3. Disable "Power Nap"