Did you forget to add a HumanoidDescription in the dummy’s humanoid? (do within script) https://devforum.roblox.com/t/view-players-outfits/273496/18?u=bolekindsdevacc
Example script:
local humanoid = dummyhumanoidhere
local desc = game.Players:GetHumanoidDescriptionFromUserId(plr.UserId)
humanoid:ApplyDescription(desc)