Windows 11 Menu box is not rounded

I have a WinForms app that is built using C# and .NET 5.0 framework. When launched on Windows 11 (preview build 21H2 22000.100) it has a nice new look (rounded corners, blue checkboxes, new TextBoxes, etc.), but one thing is missing - rounded main menu. How to fix that?

How to reproduce?

1. Visual Studio 2019
2. New Project
3. Windows Forms App C#
4. Toolbox - add menu
5. Run
6. Observe rectangular menus (but should be rounded, see the image)

thanks for reply

Try to change theme.