additional_hosts not working as expected?

The problem

I have a local SearxNG container running on http://192.168.1.XXX:YYYY and since I already had this addon running for my HA instance I'm trying to use it's additional_hosts feature instead of spinning up another entire reverse proxy.

I'm able to reach HA at https://mydomain.com and Searx at http://192.168.1.XXX:YYYY, but not at https://searx.mydomain.com. What am I missing? Am I supposed to set something through Cloudflare?

Thanks for your time.

What version of Cloudflared has the issue?

5.1.21

What was the last working version of Cloudflared?

No response

What type of installation are you running?

Home Assistant Supervised

Add-on YAML Configuration

Here's my config based on this example:

external_hostname: mydomain.com
additional_hosts:
  - hostname: searx.mydomain.com
    service: http://192.168.1.XXX:YYYY
tunnel_name: mytunnel
tunnel_token: >-
  [mytoken]

Anything in the logs that might be useful for us?

2024-10-07T14:56:59Z INF Updated to new configuration config="{\"ingress\":[{\"hostname\":\"mydomain.com\",\"originRequest\":{},\"service\":\"http://192.168.1.ZZZ:8123\"},{\"service\":\"http_status:404\"}],\"warp-routing\":{\"enabled\":false}}" version=2

Steps to reproduce the issue

Add the additional_hosts, then restart the addon.

Additional information