SSH connection issue hostname doesn't match hostname

[lightningorb]

This is a totally strange one.

~/.lightning/config

plugin=/home/ubuntu/c-lightning-REST/plugin.js
rest-port=3001
rest-docport=4001
rest-protocol=https
rest-domain=A.B.C.D

Then after starting lightningd, the contents of certs/certificate.pem and certs/access.macaroon are provided to the requests library. It works with workbench however with a hand built setup it says:

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
    return request("get", url, params=params, **kwargs)
  File ".../python3.9/site-packages/requests/api.py", line 59, in request
    return session.request(method=method, url=url, **kwargs)
  File ".../lib/python3.9/site-packages/requests/sessions.py", line 587, in request
    resp = self.send(prep, **send_kwargs)
  File ".../lib/python3.9/site-packages/requests/sessions.py", line 701, in send
    r = adapter.send(request, **kwargs)
  File ".../lib/python3.9/site-packages/requests/adapters.py", line 563, in send
    raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='A.B.C.D', port=3001): Max retries exceeded with url: /v1/getinfo (Caused by SSLError(CertificateError("hostname 'A.B.C.D' doesn't match 'A.B.C.D'")))

Same issue with rest-domain=localhost.

Clearly a user error, just not sure where to turn.

[lightningorb]

Ah. OK so: rest-domain needs to be domain (as the name implies) and not an IP.