
In the dock, click the Finder icon and then in the left panel under Devices, click your computer name.
If the encryption status of any volume or partition is No, launch Finder. Check the encryption status for each additional partition or volume. You may have to expand the window to display all the information. Find the Is encrypted line and confirm that is says Yes. Information about the selected volume displays. In the left panel, click the extra partition or volume and then click Info in the upper-right corner of the toolbar. Navigate to Applications > Utilities and launch Disk Utility app. To find the status of additional partitions or volumes: Navigating to System Preferences > Security & Privacy > FileVault reveals the status of the system partition but not any additional partitions. How to determine if your Mac is encrypted: hard drives with multiple partitions/volumes If your hard drive is in the process of being encrypted, the FileVault screen displays the encryption status. If your had drive is not encrypted, the FileVault screen displays a message saying that FileVault is turned off. If your hard drive is encrypted, the FileVault displays a message saying that FileVault is turned on. To confirm the encryption status of your Mac, navigate to System Preferences > Security & Privacy > FileVault. How to determine if your Mac is encrypted: hard drives with one partition/volume
FileVault is on and the boot volume is encrypted but additional volumes have been created that are not encrypted. Also, encryption of APFS-formatted SSD drives takes longer than encryption on HFS+-formatted SSD drives.
On large traditional hard drives the time to complete encryption can run many hours, increasing with the size of the drive.
FileVault has been enabled but encryption is not yet complete.
If you suspect this may be the case, reboot before proceeding. The system was encrypted but has not been rebooted since the encryption was completed.There are three likely reasons that an encrypted Mac would indicate that it is unencrypted in My Devices: