ADDON_LOADED does not work

[evilbib]

So this code below does nothing. No errors.
If I remove the "if addon" line it works, but then it will be executed multiple times. This did work before 6.2.

Somebody can help me?

local function ApplySkin(self, event, addon)
    if addon == "Skada" then
        local SkadaDisplayBar = Skada.displays["bar"]
        hooksecurefunc(SkadaDisplayBar, "AddDisplayOptions", function(self, win, options)
            options.titleoptions = nil
            options.windowoptions = nil
        end)
        hooksecurefunc(SkadaDisplayBar, "Create", function(self, win)
            local skada = win.bargroup          
            local skadaBorder = CreateFrame("Frame", nil, skada, skada)
            skadaBorder:SetAllPoints()
            skadaBorder:CreateBeautyBorder(12)
            skadaBorder:SetBeautyBorderPadding(3)
        end)
        hooksecurefunc(SkadaDisplayBar, "ApplySettings", function(self, win)
            local skada = win.bargroup
            skada:SetBackdrop({ 
                bgFile = "Interface\\Tooltips\\UI-Tooltip-Background", 
                edgeFile = nil, tile = false, tileSize = 0, edgeSize = 32, 
                insets = { left = 0, right = 0, top = 0, bottom = 0 }
            })
            skada:SetBackdropColor(0, 0, 0, 0.8)
        end)
    end
end
 
local f = CreateFrame("Frame")
f:RegisterEvent("ADDON_LOADED")
f:SetScript("OnEvent", ApplySkin)