Why is nmap not working in 18.04?

After fresh installs of Ubuntu 18.04 and nmap (snap install) on two separate machines, both return the same nmap error:

dnet: Failed to open device [device-name] QUITTING!

when I run the command:

sudo nmap -sn 192.168.1.0/24

Is there a new syntax I should be using?

The command works without sudo, but outputs less information.

Nmap version is 7.25SVN

Solution 1:

As the comment by WinEunuuchs2Unix suggested the way to make the snap version of nmap work (on Ubuntu 20.04 "focal fossa") is

sudo snap connect nmap:network-control

Solution 2:

As JanC already hinted at, the snap version of nmap has an issue with opening network devices when it is run as root. After removing the snap version and installing the aptitude version it worked as expected.