Notes for CM:

The source IP is going to be the same because of the provider. You need to key off something else.

Maybe "X-Forwarded-For" header is available? That would be the IP the proxy is forwarding to you, and should be provided by the proxy itself.
Could also be under "Forwarded" in the new format.

See:

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Forwarded