2018 Mac Mini - Won't boot when power applied

I work in an environment where power is turned off to the building nightly. On previous revisions of the Mac Mini, I was able to get them to automatically boot when power is applied (in the mornings) by doing the following:

• System Preferences
• Energy Saver
• Schedule...
• Start up or wake: 4:00 AM every day (or sometime in the middle of the night)

In that state, when power was applied at any time following 4:00 AM, the computer would boot.

The 2018 Mac Mini does not do this. I set the Schedule in the Energy Saver system preferences as above, but the computer does not turn on when power is applied. It does boot as scheduled if power is already hot, but not after.

Why would this model be different, and is there a way to restore that functionality?

Is FileVault enabled? If so, that would prevent the scheduled boot from working.

See here: FileVault and scheduled boot