It is somehow related to https://github.com/pulumi/pulumi-kubernetes-operator/issues/193 . And my question is how to get rid of these errors?

It looks like this error was turned into a debug message for the update path in https://github.com/pulumi/pulumi-kubernetes-operator/pull/288, but not for the refresh path. I've opened https://github.com/pulumi/pulumi-kubernetes-operator/pull/352 to apply the same change to report a debug message instead of an error on the refresh path as well.

Perfect. Thank you.