8333 failed after select(): Connection refused (111)
this happens when you have a running daemon and suddenly for whatever reason the firewall starts blocking it. IT IS A FIREWALL ISSUE.
In my case I installed additional programs on my server which changed the settings of nftables (formerly iptables). I had to open up the relevant ports again (that are required by btc-daemon).
After that you have to restart both nftables as well as btcd.
Keep checking the logs for a few minutes. And you will see it will be running just fine.