I have these @AppStorage settings and the related code to bind them and it works fine:

@AppStorage("settingsToken") private var settingsToken: String = ""
    @AppStorage("settingsUser") private var settingsUser: String = ""
    @AppStorage("settingsSlug") private var settingsSlug: String = ""

    ...
    ...

    Text("Token")
                    .font(.system(size: 17, weight: .regular, design: .rounded))
                    .foregroundColor(settingsAccentColor)
                TextField("Saved Token", text: $settingsToken)

                Text("User")
                    .font(.system(size: 17, weight: .regular, design: .rounded))
                    .foregroundColor(settingsAccentColor)
                TextField("Saved User", text: $settingsUser)

                Text("Slug")
                    .font(.system(size: 17, weight: .regular, design: .rounded))
                    .foregroundColor(settingsAccentColor)
                TextField("Saved Slug", text: $settingsSlug)

But if I add a new @AppStorage...

    @AppStorage("settingsLogo") private var settingsLogo: String = ""

...
...

                Text("Welcome logo")
                    .font(.system(size: 17, weight: .regular, design: .rounded))
                    .foregroundColor(settingsAccentColor)
                TextField("Logo", text: $settingsLogo)

I get a compile error: Trailing closure passed to parameter of type 'FormStyleConfiguration' that does not accept a closure, on the form of the NavigationView

var body: some View {

        NavigationView {
            Form {

Removing the following line prevents the compile error but clealy I need this:

                TextField("Logo", text: $settingsLogo)

I really can't see what difference adding this new @AppStorage which is exactly the same as the other does.

Note that settingsLogo will be a URL of an image, so i'm using a String.

Do you have anything other then these in the Form? Just looking at your code you have 8 views already if you have more then 2 other you will go over the 10 view limit. Try putting TOKEN, USER and SLUG in a Group enclosure.

It helps everyone figure out what's going on with your code if you post it in a coherent fashion, rather than in pieces that don't connect up to something that makes sense.

Thank you @NigelGee. Exactly, I totally forgot about the group 10 limit. (proviso : i'm 5 weeks into my swift learning, there's a lot to remember)

If that the case I would make a new SwiftUI View and put this in

struct MyTextField: View {
    let title: String
    @Binding var text: String

    var body: some View {
        VStack(alignment: .leading) {
            Text(title)
                .font(.system(size: 17, weight: .regular, design: .rounded))
                .foregroundColor(.accentColor)

            TextField("Enter \(title)", text: $text) // changed from "Saved ..." as this is placeholder and will only see it if the binding is empty
        }
    }
}

struct MyTextField_Previews: PreviewProvider {
    static var previews: some View {
        MyTextField(title: "Logo", text: .constant(""))
    }
}

Then you can use it

struct ContentView: View {
    @AppStorage("settingsToken") private var settingsToken: String = ""
    @AppStorage("settingsUser") private var settingsUser: String = ""
    @AppStorage("settingsSlug") private var settingsSlug: String = ""
    @AppStorage("settingsLogo") private var settingsLogo: String = ""

    var body: some View {
        VStack {
            MyTextField(title: "Token", text: $settingsToken)
            MyTextField(title: "User", text: $settingsUser)
            MyTextField(title: "Slug", text: $settingsSlug)
            MyTextField(title: "Logo URL", text: $settingsLogo)
        }
        .padding()
    }
}

So go from eight Views to four

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