Haproxy not working (tcp or http mode)

Installing and Using OpenWrt
1

WRT3200ACM, OpenWrt 19.07.3, haproxy 2.0.15-1

I'm at a loss. I really can't find much referencing OpenWRT/haproxy specific information. I've tried a basic cfg file like this:

global
	uid 0
	gid 0

frontend HTTPS_443
	bind *:443
	default_backend PORT_443

backend PORT_443
	server server1 192.168.0.31:443

This basic cfg should be mode tcp by default. But, I've called out mode tcp specifically too. I've tried formatting it in a "listen" configuration. Still, no joy.

Thanks in advance.

*NOTE: Firewall port 443 pass-through turned off.