Loadbalancer connected to two origins connected via cloudflare tunnel

I’m trying to set up a load balancer for a webserver. I have 2 origin servers both connected via a Cloudflare tunnel. When I point my load balancer to the hostnames with the cname for those tunnels/service. i get a 404. I can access each subdomain and access the service, but when i point the load balancer and use it’s hostname, or a dns record i point to it, i get 404. What am i doing wrong?