ss is replacing netstat, how can I get it to list ports similarly to what I am used to?

I've been trying to modernise my way with Linux by, for one thing, ditching netstat for ss. I looked up my favourite command line flag for netstat in the ss man pages, and was very glad to find that netstat -lnp is more or less the same command as ss -lnp. Or so I thought...

# ss -lnp | grep 1812

Turns up nothing, but

# netstat -lnp | grep 1812
udp        0      0 0.0.0.0:1812            0.0.0.0:*                           11103/radiusd

does. A fact that made that particular troubleshooting unnecessarily harder.

Now I'm trying to understand how I should have used ss to verify that the daemon was listening.

Can someone please explain?