Reading into that further, I believe that there might be a mis-match between some of the settings/selection of the TLS certificate…
My choice would be to use the LetsEncrypt certificate but this log seems to refer to a cockpit ws-certs nethserver.cert
The issue described in the thread was a non system php-version,
so start there:
# php -v
PHP 5.4.16 (cli) (built: Apr 1 2020 04:07:17)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2013 Zend Technologies
Do you have other (SCL) php versions installed?
# rpm -qa | grep php7