on the job page (https://app.circleci.com/pipelines/github/$org/$project/$id/workflows/$workflow_id) if a job fails, the dynamic frontend code does not allow the Rerun -> Rerun Workflow From Failed button to be available, and it remains greyed out.
A refresh of this page fixes the issue, so I suspect it’s just not updated from the AJAX/Websocket information as the rest of the app is.