keel: imagePullSecrets not found?

I just installed Keel on a Kubernetes 1.12 cluster on DigitalOcean using the provided resources. I have created a deployment with an image from a private Docker Hub repository. The default service account has the correct image pull secrets; the image gets pulled and the pods are started. (imagePullSecrets is set in the pod.)

However, I still see this in the Keel logs over and over again:

time="2018-11-14T00:41:30Z" level=error msg="trigger.poll.RepositoryWatcher.Watch: failed to add image watch job" error="Get https:/
/index.docker.io/v2/goabout/automat/manifests/master: http: non-successful response (status=401 body=\"{\\\"errors\\\":[{\\\"code\\\
":\\\"UNAUTHORIZED\\\",\\\"message\\\":\\\"authentication required\\\",\\\"detail\\\":[{\\\"Type\\\":\\\"repository\\\",\\\"Class\\\
":\\\"\\\",\\\"Name\\\":\\\"goabout/automat\\\",\\\"Action\\\":\\\"pull\\\"}]}]}\\n\")" image="namespace:default,image:index.docker.
io/goabout/automat,provider:kubernetes,trigger:poll,sched:@every 5m,secrets:[]"

So it seems Keel does not pick up the imagePullSecrets correctly?

Anything I can do to debug the problem further?