DwmEnableBlurBehindWindow not working with aero10 msstyle?

[Gameknight963]

Readme says DwmBlurGlass can restore DwmEnableBlurBehindWindow effect, and it works, but it seems to break with every single custom msstyle I have. I'm on Windows 10 19045.

Here it is with base win10 style:

If I switch the theme without closing the window, it works. Shown is Aero10.1, but other themes produced similar results.

Restarting the application breaks it though

Then, switching it back to Windows theme without closing:

This is not an issue with the OldBlur implementation:

Can anyone who is more knowledgeable than me tell me why this happens? I wasn't sure whether to create an issue because it could be an issue in a few places: DWMBlurGlass, the themes, the UxTheme patcher, or my code. (I'm using UXTheme hook windhawk mod as my UxTheme patcher.)

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);
    BackColor = Color.Black; // Color.Black is alpha zero afaik
    DWM_BLURBEHIND blur = new DWM_BLURBEHIND
    {
        dwFlags = DWM_BB_ENABLE,
        fEnable = true,
        hRgnBlur = IntPtr.Zero,
        fTransitionOnMaximized = false
    };
    Marshal.ThrowExceptionForHR(DwmEnableBlurBehindWindow(Handle, ref blur));
}

[DllImport("dwmapi.dll")]
internal static extern int DwmEnableBlurBehindWindow(IntPtr hWnd, ref DWM_BLURBEHIND pBlurBehind);

[StructLayout(LayoutKind.Sequential)]
internal struct DWM_BLURBEHIND
{
    internal uint dwFlags;
    [MarshalAs(UnmanagedType.Bool)]
    internal bool fEnable;
    internal IntPtr hRgnBlur;
    [MarshalAs(UnmanagedType.Bool)]
    internal bool fTransitionOnMaximized;
}

Another issue: it does not work with FormBorderStyle.None, pretty much no matter what I do. For you c++'ers out there, that turns off WS_CAPTION and WS_THICKFRAME. I believe this used to work on Windows 7. Using DwmBlurGlass with borderless windows is the main reason I'm interested in DwmEnableBlurBehindWindow.

(Also off topic but how do i make these posts with a bunch of images look more readable)