Report everything you have already attempted to solve your problem.
I boot from sata hdd with 2 partitions.
I installed a pcie m.2 drive that is two times the size of the sata disk.
I used 'dd if=boot_sata_hdd of=bootdisk.iso bs=1mb'
I used etcher to burn the iso to the ssd disk ..
all things being equal.. boot flags, gpt, /boot/efi etc...
the extra space on the ssd was empty space so formated it to btrfs
Using fsdisk -l , lsblk , hwinfo to identify all the devices uuid to make changes to fstab.
Failed to boot...
nvme drive has same uuid as original sata drive.