In Recovery mode I reset security preferences to none and allowed boot from external drive yet my 2018 MacBook Pro w/touchbar defaults to the internal hard drive instead of the CC clone on my Samsung evo 850 external drive which does show up in the system preferences as a bootable drive. It also shows up on the desktop. Any ideas on how to get the laptop to boot from the external SSD or why it won't? The first time I tried this was with a clone of my iMac 2015 which also is running Mojave. I wrote Bombich and they thought that might be the reason it wouldn't boot properly so I made a clone of the MacBook Pro to test that theory and I'm still having the same problem. NB: System Preferences>Startup Disk shows the Carbon Copy SSD clone as a bootable drive. Any ideas on what I'm missing here?