Self hosted web app not loading when accessing the wan IP from local network but works if accessed outside network over wan

I had self hosted nextcloud , load balanced by haproxy behind Keepalived VIP. I am able to ping all the IP addresses on local network. and checked apache2, keepalived and haproxy systemd services running as usual. nslookup resolves to my wan ip address. both port 80 and 443 of VIP that were working earlier are still forwarded to handle request from WAN, but my nextcloud is not loading, I have figured out that its not reaching haproxy at all because at root I had a redirect which is also not working. since keepalived is also up and running both master and backup I do not understand what has gone wrong. How should I start troubleshooting and what should I look for

any tip would be of great help