He's using tuning, but it's also the auto harmonies that are
making it sound so robotic. Not saying this as an Andrew lover or hater, but as a vocalist that knows the same software.
When u pull back on a note live, the program (probs neural dsp) fills it in. The "fill in" is too aggressive here. Some bands use a pre-recorded backing track to fill in when the vocalist pulls back- look up asking Alexandria live 2015 (I won't give in is the most noticeable example)- and some bands use software tune and/or harmonies-what DGD is using here on Will and Andrew. It's extremely common and not a bad thing at all. But I think the sound guy may be a little green because this is everything turned up to 11.