project-system: Setting do not work on NEW VB .Net 5 Winforms application

• .NET Core Version: What I have installed is below

Microsoft.WindowsDesktop.App 3.1.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.0-preview.2.21154.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

• Have you experienced this same bug with .NET Framework?: No

Problem description: Create a new VB WinForm App, that will read settings, add settings, run app and application will crash as below.

System.Configuration.ConfigurationErrorsException
  HResult=0x80131902
  Message=Configuration system failed to initialize
  Source=System.Configuration.ConfigurationManager
  StackTrace:
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   at System.Configuration.ClientConfigurationSystem.PrepareClientConfigSystem(String sectionName)
   at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.RefreshConfig(String sectionName)
   at System.Configuration.ConfigurationManager.RefreshSection(String sectionName)
   at System.Configuration.ClientSettingsStore.ReadSettings(String sectionName, Boolean isUserScoped)
   at System.Configuration.LocalFileSettingsProvider.GetPropertyValues(SettingsContext context, SettingsPropertyCollection properties)
   at System.Configuration.SettingsBase.GetPropertiesFromProvider(SettingsProvider provider)
   at System.Configuration.SettingsBase.GetPropertyValueByName(String propertyName)
   at System.Configuration.SettingsBase.get_Item(String propertyName)
   at System.Configuration.ApplicationSettingsBase.GetPropertyValue(String propertyName)
   at System.Configuration.ApplicationSettingsBase.get_Item(String propertyName)
   at CareLink.My.MySettings.get_username() in C:\Users\PaulM\Source\Repos\CareLink\CareLink\My Project\Settings.Designer.vb:line 62
   at CareLink.LoginForm1.LoginForm1_Load(Object sender, EventArgs e) in C:\Users\PaulM\Source\Repos\CareLink\CareLink\LoginForm1.vb:line 12
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.ContainerControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, WM msg, IntPtr wparam, IntPtr lparam)

  This exception was originally thrown at this call stack:
    [External Code]

Inner Exception 1:
ConfigurationErrorsException: Unrecognized configuration section system.diagnostics. (C:\Users\PaulM\Source\Repos\CareLink\CareLink\bin\Debug\net5.0-windows\CareLink.dll.config line 8)

Expected behavior: I can read settings

Minimal repro: Contents of .config file

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System.Configuration.ConfigurationManager, Version=5.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51" >
            <section name="CareLink.My.MySettings" type="System.Configuration.ClientSettingsSection, System.Configuration.ConfigurationManager, Version=5.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
        </sectionGroup>
    </configSections>

Manually deleting system.diagnostics section fixes the issue until a rebuild.

    <system.diagnostics>
        <sources>
            <!-- This section defines the logging configuration for My.Application.Log -->
            <source name="DefaultSource" switchName="DefaultSwitch">
                <listeners>
                    <add name="FileLog"/>
                    <!-- Uncomment the below section to write to the Application Event Log -->
                    <!--<add name="EventLog"/>-->
                </listeners>
            </source>
        </sources>
        <switches>
            <add name="DefaultSwitch" value="Information" />
        </switches>
        <sharedListeners>
            <add name="FileLog"
                 type="Microsoft.VisualBasic.Logging.FileLogTraceListener, Microsoft.VisualBasic, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL"
                 initializeData="FileLogWriter"/>
            <!-- Uncomment the below section and replace APPLICATION_NAME with the name of your application to write to the Application Event Log -->
            <!--<add name="EventLog" type="System.Diagnostics.EventLogTraceListener" initializeData="APPLICATION_NAME"/> -->
        </sharedListeners>
    </system.diagnostics>

From here down works

    <userSettings>
        <CareLink.My.MySettings>
            <setting name="username" serializeAs="String">
                <value />
            </setting>
            <setting name="password" serializeAs="String">
                <value />
            </setting>
        </CareLink.My.MySettings>
    </userSettings>
</configuration>