In my case running Traefik on docker I was not getting real ip addresses. I changed the NLB option Source header (IP, port) preservation: Enabled
To change this you need to remove the targets from the backend set first.
At the same time suddenly the console did not allow me to add the VM.Standard.A1.Flex server back into the backend set. It required me to upgrade to a paid account. Which is nonsense since I used this server as a target for a long time and now suddenly they want to be sneaky with free options. At least the CLI did add the IP back in.
❯ ocicli nlb backend create --backend-set-name server01-443 --network-load-balancer-id
--port 443 --ip-address 10.0.10.226