Trusted proxies

I used the add on Cloudflared to access the iOS app remotely. The instructions say you have to add trusted proxies to the config. - 172.30.33.0/24 .Ater a restart the the app times out. Adding - 172.30.0.0/16 gets it to work. Can someone explain why the original recommended by Cloudflared doc doesn’t work?

My setup is a Proxmox server running HA KVM install.

Did you just add the exact same IP from the example docs instead of the actual IP of your proxy?

Yes
The doc say there is no need to adapt anything as the IP range in docker is always the same.
How would I find my docket IP?