I understand that OpenSSL version 1.1.1 is required which is not shipped with SLES12SP4 (includes openssl-1.0.2j). SLES15 ships with the required OpenSSL version.
This is now an issue as Chrome updates are making unreliable connections to the MAG ESP. Disabling TLS1.3 in chrome does resolve the issue but end user browser configuration isn't a viable solution.