Per https://github.com/ComplianceAsCode/content/blob/master/applications/openshift/etcd/etcd_unique_ca/rule.yml#L40C36-L40C115, it will check the path /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt on the node. However, the path doesn't exists on node:
 % oc debug node/ip-10-0-28-255.us-east-2.compute.internal                        
Starting pod/ip-10-0-28-255us-east-2computeinternal-debug-mkvp8 ...
To use host binaries, run `chroot /host`
Pod IP: 10.0.28.255
If you don't see a command prompt, try pressing enter.
sh-5.1# ls /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt
ls: cannot access '/host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt': No such file or directory
sh-5.1# ls /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/
etcd-all-bundles  etcd-scripts restore-etcd-pod
sh-5.1# exit
exit
Removing debug pod ...

4.17.0-0.nightly-2024-06-13-010514 + cov1.5.0

Always

1. Install CO 
2. Create a ssb$ oc compliance bind -N test profile/ocp4-cis-node 

The rule ocp4-etcd-unique-ca gets FAIL by default for 4.17 payload. Details seen from the description
% oc get ccr | grep etcd-unique-ca
ocp4-cis-node-master-etcd-unique-ca                                           FAIL     medium

The rule ocp4-etcd-unique-ca gets PASS by default

The issue is for 4.17 only. It doesn't exists for other releases.