Cross-report drillthrough not working

I'm trying cross-report drillthrough for the first time, and basing on the GITC video, I did the following:

• Both reports are in the same premium workspace
• Both reports have Cross-report drillthrough enabled in the Current File options and in the service
• Target report has Cross-report enabled in the Drill through settings using the Employee[ID] column

• Imported into the Source report the Employee table from the Target report dataset (so technically, they are the exact same tables - no changes have been made to this imported table)

Published both reports and I see there's no drillthrough option in the Source table that uses data fields from the imported table used for the drillthrough. Am I missing something or did something wrong here?