Picker count not updating when array changes

I have created two pickers, one Category picker, and one Item picker, in separate views. Based on excellent input in an earlier question, my Category picker now successfully filters Items in the Item picker and selects the first Item in the selected Category.

On the surface, everything looks OK, but the count of items in the Item picker doesn't update after I select a new Category. It retains the count from the originally initialized Category even though the array it is based on now has more items in it.

Image and Video of below app and issue can be found here:

https://imgur.com/a/eqyrgbF

Is there some syntax issue I am overlooking, or am I approaching it completely wrong?

/*
Situation:
Two pickers, one selecting a category and the other selecting the items in that category.

Challenge:
The second picker shows the right items, but with the Count from the first category.

To see issue, copy below code into ContentView on a single-view app.
*/


import SwiftUI

struct Item: Identifiable {
    var id = UUID()
    var category:String
    var item:String
}

let myCategories:[String] = ["Category 1","Category 2"]

let myItems:[Item] = [
    Item(category: "Category 1", item: "Item 1.1"),
    Item(category: "Category 1", item: "Item 1.2"),
    Item(category: "Category 2", item: "Item 2.1"),
    Item(category: "Category 2", item: "Item 2.2"),
    Item(category: "Category 2", item: "Item 2.3"),
    Item(category: "Category 2", item: "Item 2.4"),
]

class MyObject: ObservableObject {
    
    // Select Category variables
    @Published var selectedCategory:String = myCategories[0]
    @Published var selectedCategoryItems:[Item] = []
    @Published var selectedCategoryInt:Int = 0 {
        didSet {
            selectCategoryActions(selectedCategoryInt)
        }
    }
    // Select Item variables
    @Published var selectedItem:Item = myItems[0]
    @Published var selectedItemInt:Int = 0 {
        didSet {
            selectedItem = selectedCategoryItems[selectedItemInt]
        }
    }
    
    // Initialize values
    init() {
        selectCategoryActions(selectedCategoryInt)
    }
    
    // Actions when selecting a new category
    func selectCategoryActions(_ selectedCategoryInt:Int) {
        selectedCategory = myCategories[selectedCategoryInt]
        
        // Get items in category
        selectedCategoryItems = myItems.filter{ $0.category.contains(selectedCategory)}
        
        // Select item in category
        let selectedItemIntWrapped:Int? = myItems.firstIndex { $0.category == selectedCategory }
        if let selectedItemInt = selectedItemIntWrapped {
            self.selectedItem = myItems[selectedItemInt]
        }
    }
}



// Picker for selecting a category
struct SelectCategory: View {
    var myCategories:[String]
    @Binding var selectedCategoryInt:Int
    var body: some View {
        VStack {
            Picker(selection: self.$selectedCategoryInt, label: Text("Select category")) {
                ForEach(0 ..< self.myCategories.count, id: \.self) {
                    Text("\(self.myCategories[$0])")
                }
            }.labelsHidden()
        }
    }
}

// Picker for selecting items within the category
struct SelectItem: View {
    var selectedCategoryItems:[Item]
    @Binding var selectedItemInt:Int
    var body: some View {
        VStack {
            // MARK: Something is going wrong here. I don't get right Item ID's
            Picker(selection: self.$selectedItemInt, label: Text("Select item")) {
                ForEach(0 ..< self.selectedCategoryItems.count, id: \.self) {
                    Text("\(self.selectedCategoryItems[$0].item)")
                }
                /*ForEach(selectedCategoryItems, id: \.id) { item in
                    Text("\(item.content)")
                }*/
            }.labelsHidden()
        }
    }
}

struct ContentView: View {
    @ObservedObject var myObject = MyObject()

    var body: some View {
        VStack(alignment: .center, spacing: 10) {
            Text("When selecting Category 2, only two of the four items are shown.")
            Text("Selected category: \(myObject.selectedCategory)")
            Text("Items in category: \(myObject.selectedCategoryItems.count)")
            Text("Selected item: \(myObject.selectedItem.item)")
            SelectCategory(
                myCategories: myCategories,
                selectedCategoryInt: self.$myObject.selectedCategoryInt)
            
            SelectItem(
                selectedCategoryItems: self.myObject.selectedCategoryItems,
                selectedItemInt: self.$myObject.selectedItemInt)
            Spacer()
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}