I have a 2016 iMac with a fusion drive and an external usb drive for storing files. I want to restore my whole system including the OS and the USB drive. I boot the iMac into recovery mode, go to Time Machine, select the backup I want to restore, then on the next screen where I want to restore to, it only shows my USB drive. Why doesn’t it show myMacintosh HD drive? If I go to the disk utility, I can see the fusion drive there.