Ground personnel reported DG was assigned to the aircraft on the load plan but there was no DG to load. Aircraft returned to the gate to ensure no DG was loaded.

Narrative

I was assigned Aircraft X ZZZ to ZZZ1. When I sign in; I see a Dangerous Good (DG) is assigned to the flight. When I see the load plan; I went into the building and assign the DG bin location as F2. As is our custom before loading the flight to deliver the DG notification to the Captain; I did just that. I later go down to inspect the freight cart to made sure it wasn't mixed with the freight boxes. I did not see or receive any DG for that flight. Ask the crew if they locate a dry ice container to notify me immediately. I continue to look for the DG; in the carts with bags. I continue to load the flight and there was no DG notification when I finalized the flight. They call me on the radio to ask if I had any DG inside the aircraft and I reply no DG was onboard. I was in leave for a year; I did forget how to refuse DG in the system; after it has been assigned. Aircraft returned to the gate to be offloaded to ensure no DG was on the cargo bin. Captain should ask me if DG was loaded; before beginning to ask Tower for pushback clearance.