The operator does not claim support for disconnected environments through the annotation: operators.openshift.io/infrastructure-features: '["disconnected"]'
It is however marked as supporting disconnected installation in this solution article: https://access.redhat.com/articles/4740011.
Note that the knowledge article will be decommissioned in favour of our customers directly seeing what operator supports disconnected installation directly in OperatorHub and the Red Hat Container Catalog.

Action: Add the annotation for disconnected support.

The annotation is documented here:
https://docs.openshift.com/container-platform/4.8/operators/operator_sdk/osdk-generating-csvs.html#olm-enabling-operator-for-restricted-network_osdk-generating-csvs

Lastly, if you do specify this annotation, ensure your QE process includes the testing of the operator in a disconnected environment. There are also annotations for FIPS and PROXY support you will want to review, if the operator supports these, add those annotations into the ClusterServiceVersion as well.