How do I disable a button while it has focus

I have a view that shows a table and 4 buttons. Each button allows the user to step forward and backwards through the data. Buttons are enabled and disabled based on where you are in the data. If you are less than 200 values to the end of the data for example, the "Page Down - 200" button is disabled. Everything works fine if the mouse is used to run the code associated with each button. But in this case I think the buttons never get focus. Focus I think remains with the sidebar content item that brought up the table view (am using a navigation split view). If I tab over to the page down 200 button and use the space bar to run its associated code I get the error "AttributeGraph: cycle detected through attribute 864480". I think the problem lies with attempting to disable the button while it has focus but am not 100% sure. I have tried to change the focus prior to disabling the button but I get the same error. I think there is some fundamental that I am missing. Below is my table view along with the page down 200 button view.

struct DataTable: View {

    @FocusState var buttonWithFocus: Field?
    
    @ObservedObject var vm: ButtonsViewModel = ButtonsViewModel.shared
    @State private var hasAppeared = false
    
    var closingValues: [TradingDayClose]
    var heading: String = ""
    
    init(fundName: String, closingValues: [TradingDayClose]) {
        self.heading = fundName
        self.closingValues = closingValues
    }
    
    var body: some View {
        
        HStack {
            Spacer()
                .frame(width: 150)
            GroupBox(heading) {
                if hasAppeared {
                    Table (of: TradingDayClose.self) {
                        TableColumn("") { closingValue in
                            Text(dateToStringFormatter.string(from: closingValue.timeStamp!))
                                .id(closingValue.timeStamp!)
                                .textFormatting(fontSize: 14)
                                .frame(width: 100, alignment: .center)
                        } // end  table column
                        TableColumn("") { closingValue in
                            Text(String(format: "$ %.2f", closingValue.close))
                                .textFormatting(fontSize: 14)
                                .frame(width: 100, alignment: .center)
                        } // end  table column
                    } rows: {
                        ForEach((closingValues.indices), id: \.self) { index in
                            if vm.showData[index] == true {
                                TableRow(closingValues[index])
                            }
                        }
                    }
                    .focusable(false)
                    .frame(width: 250)
                    .overlay {
                        let tempValue1: String = "Date"
                        let tempValue2: String = "Closing Value"
                        Text(tempValue1).position(x: 63, y: 15)
                            .textFormatting(fontSize: 16)
                        Text(tempValue2).position(x: 180, y: 15)
                            .textFormatting(fontSize: 16)
                    }
                } // end has appeared
            } // end group box
            .groupBoxStyle(Table2GroupBoxStyle())
            Spacer()
                .frame(width: 50)
            VStack {
                Spacer()
                    .frame(height: 100)
                
                Form {
                    Section {
                        ButtonUp25(closingValuesCount: closingValues.count)
                            .focused($buttonWithFocus, equals: .btnUp25)
                        ButtonUp200(closingValuesCount: closingValues.count)
                            .focused($buttonWithFocus, equals: .btnUp200)
                    } header: {
                        Text("Page Up")
                    }
                    Spacer()
                        .frame(height: 20)
                    Section {
                        ButtonDown25(closingValuesCount: closingValues.count)
                            .focused($buttonWithFocus, equals: .btnDn25)
                        ButtonDown200(buttonWithFocus: $buttonWithFocus, closingValuesCount: closingValues.count)
                            .focused($buttonWithFocus, equals: .btnDn200)
                    } header: {
                        Text("Page Down")
                    }
                 } // end form
                .navigationTitle("Data Table")

                Spacer()
                    .frame(height: 100)
            } // end v stack
            Spacer()
                .frame(width: 50)
        } // end h stack
        .onAppear {
            vm.InitializeShowData(closingValueCount: closingValues.count)
            vm.InitializeIndexes()
            vm.InitializeButtons()
            for i in vm.startIndex...vm.endIndex {
                DispatchQueue.main.asyncAfter(deadline: .now() + vm.renderRate * Double(i)) {
                    vm.showData[i] = true
                } // end dispatch queue main async
            }
            hasAppeared = true
        }
    } // end body
} // end struct

struct ButtonDown200: View {
    
    var buttonWithFocus: FocusState<Field?>.Binding
    
    @ObservedObject var vm: ButtonsViewModel = ButtonsViewModel.shared
    var closingValuesCount: Int
    
    var body: some View {
        
        Button("Page Down - 200") {
            
                for i in vm.startIndex...vm.endIndex {
                    vm.showData[i] = false
                }
                vm.startIndex = vm.startIndex + 200
                vm.endIndex = vm.startIndex + 24
                
                var j: Int = 0
                for i in vm.startIndex...vm.endIndex {
                    DispatchQueue.main.asyncAfter(deadline: .now() + vm.renderRate * Double(j)) {
                        vm.showData[i] = true
                    }
                    j = j + 1
                }
            
            if (closingValuesCount - 1) - (vm.startIndex + 200) < 25 {
//                buttonWithFocus.wrappedValue = .btnDn25
                vm.pageDownDisabled200 = true
            }
            if vm.startIndex > 24 {
                vm.pageUpDisabled25 = false
            }
            if vm.startIndex - 200 >= 0 {
                vm.pageUpDisabled200 = false
            }
        }
        .controlSize(.large)
        .buttonStyle(.borderedProminent)
        .disabled(vm.pageDownDisabled200)
    }
}