I am currently struggling to get FreeSWITCH (1.10.5-release-17-25569c1631~64bit) to send the intermediate CA certificate for a Let's Encrypt X.509 certificate to be used for protecting SIPS traffic.

I included the certificate chain in agent.pem:

-- 8< --

-----BEGIN EC PARAMETERS-----
*REDACTED*
-----END EC PARAMETERS-----
-----BEGIN EC PRIVATE KEY-----
*REDACTED*
-----END EC PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
*SERVER CERT*
-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----
*INTERMEDIATE CERT*
-----END CERTIFICATE-----

-- 8< --

Still, clients are complaining about an invalid CA and openssl s_client hints at only the server cert being sent in the server hello.

What did I miss?