When a Windows partition is cloned, only one of the two Windows installations is accessible.
This is due that the boot loader is using the GUID to identify which partition to boot from.
If there are two, with the same ID …

When a Windows partition is beeing cloned (using GParted for example …), the system will reject to recognize it (and not even display it). Therefore, the partition identifier needs to be changed.

To change the ID of a disk:

In cmd.exe or a Power Shell enter: diskpart. List all disks using list disk. Select the disk you want to change (most likely the one which is offline): select disk N, where N is the number of the list printed by list disk. Type uniqueid disk to see the current disk id. It will be identical to the system disk for cloned disks. Change the disk id of the old SSD by typing uniqueid disk id=12345678. The id might be a 32-bit id (like in this example, for a disk having an MBR) or a 128-bit UUID. Just change the last hex digit to something else. exit Disconnect the drive and reconnect it. The disk (its partitions) should now be recognized.