Initially, i don’t change anything in certs. Just deploy single-node rancher without DNS name, then create new custom cluster using docker run commands from GUI). I have a nginx reverse-proxy for accessing rancher GUI with https.
Some time ago, i had tried to change rancher server name to public DNS, using Let’s Encypt certs for https. With no success, my cluster lost connection to rancher server. I had restored from backup. It was few month ago, i do a few rancher and kubernetes upgrades from this time.
Probably this is an issue.
Here is a my old topic with no replies Switch to Let's Encrypt