NAT works but port forwarding does not

[Zeno Lee]

I am just starting off with PF.  I had it compiled into the kernel in 5.3 
stable.  I have not setup any rules yet.  I'm just trying to set up NAT and 
forwarding.

My network setup

Internet <----> em0 | FreeBSD | em1 <----->  LAN


my pf.conf file only has:

ext_if="em0"
int_if="em1"
webserver="192.168.1.54"

nat on $ext_if from $int_if:network to any -> ($ext_if)
rdr on $ext_if from any to any port 80 -> $webserver


NAT works, however, I cannot get port forwarding to work.  I am testing it 
vial a remote  computer on the internet whose packets only come through em0.

Am I missing anything here?