This is coming from https://github.com/openshift/cluster-node-tuning-operator/pull/154/files#r490879231 not a bug for now.
PR has been loaded in 4.6 latest build, $ oc adm release info --commits registry.svc.ci.openshift.org/ocp/release:4.6.0-0.nightly-2020-09-22-213802 | grep hyperkube hyperkube https://github.com/openshift/kubernetes 8a3992442e05b8303958d3baeb6d67344fc0c73b $ git log --date local --pretty="%h %an %cd - %s" 8a39924 | grep ' #362 ' 51a176c5f54 OpenShift Merge Robot Tue Sep 22 11:19:33 2020 - Merge pull request #362 from sttts/sttts-preserve-unknown-fields-array-openshift Will observe the tests https://prow.ci.openshift.org/job-history/gs/origin-ci-test/pr-logs/directory/pull-ci-openshift-cluster-node-tuning-operator-master-e2e-aws some days, check if there are still error ‘array should have exactly one sub-item’ can be found.
Checked from https://search.ci.openshift.org/?search=should+check+if+kubectl+diff+finds+a+difference+for+Deployments&maxAge=48h&context=1&type=bug%2Bjunit&name=&maxMatches=5&maxBytes=20971520&groupBy=job, can't find the error again: error: SchemaError(io.openshift.tuned.v1.Tuned.spec.recommend.match.match): array should have exactly one sub-item I think we could move to verified status.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (OpenShift Container Platform 4.6 GA Images), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:4196