How are you adding the layers to the map? Are you doing it in Map Viewer, Map Viewer Classic, within the Field Maps web app, or from the item details page (Add to new map)?
It's not really duplicating the name. If a Feature layer containing multiple layers is added to a map, the format is "<Feature Service Item Name> - <Layer Name>". So I'm guessing your item name is "Division 05 Survey Lines" and you have a layer that is also named "Division 05 Survey Lines" within in.