I had installed sudo in HP UX 11.3 and it is working fine but not able to make entry required to set permission similar to ROOT without using password (PASSWD) change option for define user in /etc/sudoers file
Please can you post your /etc/sudoers so we can consider where the problem may be. There is unlikely to be anything sensitive in it, but you may prefer to change the user names from your format to just User1, User2, etc.