我试过你的代码，测试过不同的场景，但我不知道为什么会发生这种情况，我唯一能说的是，不知何故，这与将本地化存储在变量中有关。
如果你直接将值存储为文本视图，它就能工作。我希望这对你有帮助。

struct ContentView: View {
    private let fontWeightNames: [Text] = [
        Text("Ultra Light", comment: "Ultra Light comment"),
        Text("Thin", comment: "Thin comment"),
        Text("Light", comment: "Light comment"),
        Text("Regular", comment: "Regular"),
        Text("Medium", comment: "Medium comment"),
        Text("Semibold", comment: "Semibold comment"),
        Text("Bold", comment: "Bold comment"),
        Text("Heavy", comment: "Heavy"),
        Text("Black", comment: "Black comment")
    ]
    private var fontWeights: [Text] {
        [fontWeightNames[2], fontWeightNames[1]]
    }
    private var currentFontWeight: Text {
        fontWeightNames[1]
    }
    private var currentFontWeightName: Text {
         fontWeightNames[fontWeights.firstIndex(of: currentFontWeight)!]
    }
    
    var body: some View {
        currentFontWeightName
    }
}