Mutual tls/ssl on elasticsearch

Server sends

*** CertificateRequest

and client replies with the certificate

*** Certificate chain
chain [0] = [
[
  Version: V3
  Subject: CN=instance
  Signature Algorithm: SHA256withRSA, OID = 1.2.840.113549.1.1.11
  ....

and server trusts it

***
Found trusted certificate:

That shows that your client is still sending the certificate so we should focus on this.

I unfortunately have no other ideas about winSSL/schannel and why it automatically picks up the certificate, or how you'd stop it from doing so.