Confirm you want to disable FileVault by clicking Restart & Turn Off Encryption. Your Mac now restarts. After you log back in using an account with FileVault permission, macOS begins decrypting ...

Disable or Update FileVault If any accounts are using the legacy FileVault, then you can disable it. To do this, log in with the account and access the Security system preferences, ...

To turn off automatic login on your FileVault 2-encrypted Mac, go to System Preferences > Users & Groups > Login Options and make sure that "Off" is selected from the drop-down.

All good things must come to an end, we’re told, and macOS 10.13 was the very end of the original FileVault, Apple’s file encryption format introduced in OS X Panther 10.3.