Can’t increase partition size of cloned volume in Mac OS X 10.11 (El Capitan)

In general, when you use those hardware-only cloning devices—like that ICY BOX you mention—you end up in situations like this. Perhaps there is a cleaner way to recover from a situation like this, but in my experience what you are attempting to do just won’t work; hardware cloning like that is strictly one-to-one as far as volume size goes. And if the target volume size is larger than the source size, the situation that you are in happens; the volume is cloned but the maximum destination volume size becomes exactly the same as the source volume size.

What I always do for cases like this—cloning smaller drive to larger drive—is to hook up the new drive to the machine in some way (such as an external USB enclosure) and then clone it via rsync or Carbon Copy Cloner. This strictly copies OS level data from one device to another; not partition data/info so this always works right off the bat.

If you clone a disk with APFS containers to a larger disk, you'll need to repair the partition before trying to resize the container. I found the answer posted by user @Ilya-K in this thread https://apple.stackexchange.com/a/390791/394570

basically, diskutil list to get a list of disks. Find the disk you want to edit, usually disk0 in a single disk system. Then diskutil repairdisk disk0 and you'll get a warning about potential data loss, but since this is a clone, you should be safe. If this is not a clone, backup first. This will repair the partition map so it see the entire new disk. Then resize the APFS container with diskutil apfs resizeContainer disk1 0 where disk1 is the APFS container shown from the diskutil list command, and 0 means use all remaining available space.