Self hosting from within network on duckdns get Rejected request from RFC1918 IP to public server address on firefox only but chrome works fine. Just wondering if any openwrt tweaks I could do where this would not flag. Perfectly aware I can just connect with private ip with cert warning or connect to a vpn. If nothing can be done will gladly close this.
If you are able to reach your server from one browser and not another, that points to the configuration of the browser itself, not your router.
Have you tried this firewall setting on the web GUI?
It's under the advanced tab of your Port Forward rule.
Gave it a try with both external and internal both flagged