@adakatsu is mentioning 9.9.1
System Manager Classic was discontinued in 9.8... (your link)
Also mentioned the "Web Screen", so I guess using the "new" RESTful API based System Manager.
A screen shot of the "Wizard" before completion might be helpful, to find out why the LIF was not created.
In addition to the commands mentioned by @aladd you might want to check
::> net port show
(I do not expect the NFS LIF to appear the the "net int show" list, since apparently it was not created...)