I have an Excel add-in that displays a WPF window on the startup

        private void ThisAddIn_Startup(object sender, EventArgs e)
    {
        GetOfficeVersion();
        
        Application.WorkbookOpen += Application_WorkbookOpen;
        Application.WorkbookAfterSave += Application_WorkbookAfterSave;
        
        
        
        TestInputsUI.Instance.Show();
    }

Nothing special about the code the TestInputsUI.Instance.Show(); is my wpf window
the problem is when I open a workbook and try to type inside the wpf textbox it sends my input to the active cell instead of the ‘textBox’
this can be simply avoided by showing the wpf as Dialog but that will freeze all interactions with the Excel app until the dialog is closed.
I tried to force the focus to the textbox and even do it in a timed loop, but nothing works