@ckrnkfrnchmn the reason you see updates in the terminal using apt-get upgrade and not system settings, is because system settings doesnt use apt, apt isnt officially supported by Ubuntu Touch.
You can use apt but thats on your back if anything breaks, and you may need to reinstall apps installed via apt again after certain updates, Libertine is the only way to officially use apt, but that can still be hit or miss due to relying on 16.04 repos if youre on xenial, and I dont beleive it works yet on Focal.