Stop node #1. Put these lines:
pxc-encrypt-cluster-traffic=ON
ssl-key=/home/adminuser/server-key.pem
ssl-ca=/home/adminuser/ca.pem
ssl-cert=/home/adminuser/server-cert.pem
inside [mysqld]
Remove the ENTIRE [sst] section.
Remove “wsrep_provider_options”.
Bootstrap node 1. Put the SAME CONFIG as above into the other nodes. Start them normally.