Why is my save marked as Modded?

A little background I started a fresh playthrough modded and didn't touch my first save. On my first save I am level 44 and saved it right before going into ng+. Well after seeing the new update I wanted to do NG+ so I uninstalled all mods. Deleted the game then deleted the game folder. Did a fresh install but whenever I save on my Original character(the non modded one) it flags the save as modded. WHY?!