Kubernetes: Failed to pull image from private container registry
Could this be due to your container name possibly? I had an issue where I wasn't properly prepending the ACR domain in front of the image name in my Kubernetes YAML which meant I wasn't pointed at the container registry / image and therefore my secret (which was working) appeared to be broken.
Can you post your YAML? Maybe there is something simple amiss since it seems you are on the right track from the secrets perspective.
How to pass image pull secret while using 'kubectl run' command?
This should help, you need to override the kubectl command with "imagepullsecrets":"cisecret".