I am using Kali to follow along and nmap was 7.40 like yours is in the course. I made the mistake of updating the OS, which upgraded nmap to 7.5. Seems like a good idea, no ? Not exactly, but I shouldn’t be surprised, 'tis the nature of software ;). Some of the options are a bit different, not a huge thing but I have to take it into account. For example these two commands:
nmap 192.168.0.1-50 -sL --dns-server 192.168.1.1
nmap 192.168.0.1-255 -PO1,2,4 -sn -v
do not show the device names as they did for you at 7.40. I could restore my VM to a prior snapshot to get it back but I think I would rather just live with it.