[Fizzlemizz]

Just tried

/run CastingBarFrame:ClearAllPoints(); CastingBarFrame:SetPoint("CENTER", UIParent, "CENTER", 0, 0)

Edit and after a /reload, /run CastingBarFrame:ClearAllPoints(); CastingBarFrame:SetPoint("CENTER", UIParent)

Both worked.

It might be a matter of when you're running your code. If it's during ADDON_LOADED or just as your .lua files are loading, Blizzard may be resetting the bar later in the load process like OnEvent for the Totem frame. PlayerFrame_AdjustAttachments() gets called from various places depending on class.