Mesos slave fails to connect after enabling ssl

Mesos agent fails to connect to the master after setting the following variables:
LIBPROCESS_SSL_ENABLED=1
LIBPROCESS_SSL_KEY_FILE=/etc/mesos/conf/ssl/server.key
LIBPROCESS_SSL_CERT_FILE=/etc/mesos/conf/ssl/server.pem
LIBPROCESS_SSL_REQUIRE_CERT=false
LIBPROCESS_SSL_VERIFY_SERVER_CERT=false
LIBPROCESS_SSL_REQUIRE_CLIENT_CERT=false
LIBPROCESS_SSL_HOSTNAME_VALIDATION_SCHEME=openssl
LIBPROCESS_SSL_VERIFY_CERT=false
LIBPROCESS_SSL_CA_DIR=/etc/mesos/conf/ssl
LIBPROCESS_SSL_CA_FILE=/etc/mesos/conf/ssl/ca.pem
LIBPROCESS_SSL_SUPPORT_DOWNGRADE=false
LIBPROCESS_SSL_VERIFY_IPADD=false
#LIBPROCESS_SSL_ENABLE_TLS_V1_2=true

Error in logs:
Failed to accept socket: Failed accept: connection error: error:1407609C:SSL routines:SSL23_GET_CLIENT_HELLO:http request

Connectivity works after setting:

LIBPROCESS_SSL_SUPPORT_DOWNGRADE=true

But then the sandbox fails to open in the web UI:

Potential reasons:

• The agent is not accessible
• The agent timed out or went offline

With the following error in the logs:

Failed to recv on socket 38 to peer 'unknown': Failed recv, connection error: Connection reset by peer