The disk to which the backup was being restored must have been using MBR partition table before. Doing so causes the GPT partition table to overwrite the data on the destination drive.

Also, do note that according to this article from Apple, it might be sufficient to clone or install the system to an external GUID-partitioned disk, boot from that, and install the firmware update ...

In the next step, you need to select the partition style. It is suggested to use MBR instead of GPT or GUID Partition Table. After clicking the OK button, your disk should initialize and run ...

The format used to define the hard disk partitions in computers with UEFI startup firmware. The GUID Partition Table (GPT) replaces the previous master boot record (MBR). GPT partitions can hold ...

GUID Partition Table: this is how Intel Macs organize their boot disks. You can put partitions with any of the supported file systems on a GUID disk, but only Macs running Mac OS 10.4 can access ...

Look under the Identifier header for the names of the disk’s partitions; for example, disk2s2. (Ignore any partitions labeled GUID_partition_scheme or EFI.) ...

Now with a little bit of searching I've found a Windows based tool that claims it can recover a GUID partition table called Partition Guru Professional Edition (the free version does not handle ...

If you want to use Disk Utility to format—and more often than not, re-format—a drive in macOS, you may sometimes want to first choose the scheme for backwards or multi-platform compatibility.