Using the Mass Updates Tile via My Client Groups

We are currently reviewing the 26D Patch notes, particularly 'Redwood Experience for Mass Assignment Changes'. We currently do not have access to the classic page, and so to do some pre-investigation I have added both 'PER_MANAGE_MASS_UPDATES_WORK_AREA_PRIV' privilege and 'PER_WORKER_MASS_ASSIGNMENT_CHANGE_PRIV' to the 'MyHR Integration Specialist' job role. I have ran all relevant scheduled processes and used a sandbox to publish the tile. However, when I go to My Client Groups > Mass Updates nothing appears when I search for different tasks (screenshot attached). Please can someone advise to how get the classic page working & useable so