I run a publicly accessible web server at home, behind an OpenWrt router. The router has firewall rules allowing incoming connections to ports 80 and 443 (forwarding rules for ipv4; port access rules for ipv6).
A recent snapshot upgrade made the web server unreachable from LAN using ipv4, while still being reachable from WAN. Ipv6 is unaffected and works as expected from both LAN and WAN.
Setup a web server inside your LAN network and confirm that it can be reached from outside. I use my phone's 4G connection for that.