I took a Time Machine backup to an external drive from old MacBook (Sierra) and then put it to a new one (High Sierra automatically) using macOS Recovery and "Restore From Time Machine Backup". Drive on the old Macbook was encrypted using FileVault but the backup I took wasn't encrypted as it takes ages to encrypt one.
Installation went fine and I was able to boot and setup the new MacBook, but now I can't turn on the FileVault. Trying to do so says "FileVault can’t be turned on for the disk “Macintosh HD”. Some disk formats don’t support the recovery partition required by encryption. To use encryption, reinstall this version of Mac OS X on a reformatted disk". I erased the data on the disk when using Restore from Time Machine and I thought it would've done the partition that way that using FileVault is possible. How should I make sure that if I now do Restore from Time Machine again it correctly sets up the disk for FileVault?