There are a number of posts in the forum about that, here a recent one: Clone Linux with GParted? - #3 by 6x12 .
I have copied a hdd to ssd using gparted of a live manjaro usb without any issues, however, this was a straightforward setup with ext4 partitions and no encryption.
As mentioned in the above linked post, it seems necessary to first decrypt the LUKS partition, then copy it to the ssd and afterwards reinstall grub (or edit fstab accordingly).