Cloudflared tunnel error "Failed to proxy HTTP Unable to reach the origin service"

What is the name of the domain?

What is the error message?

"Failed to proxy HTTP: Unable to reach the origin service. The service may be down or it may not be responding to traffic from cloudflared

What is the issue you’re encountering

My tunnel is up, but my site fails its healthcheck in the load balancer. when i enable debug logging on the tunnel in windows, it has the error: “Failed to proxy HTTP: Unable to reach the origin service. The service may be down or it may not be responding to traffic from cloudflared: read tcp a.b.c.d:51139->a.b.c.d:443: wsarecv: An existing connection was forcibly closed by the remote host.”,“time”:“2025-01-24T15:19:26Z”,“message”:“failed to serve incoming request”} . But when i use curl with the same parameters, it is successfull.

What steps have you taken to resolve the issue?

I have tried disabling http2 on the cloudflare portal.
windows firewall is disabled on this windows server.

What are the steps to reproduce the issue?

start cloudflared, read the tunnel log on my windows server.

Screenshot of the error