WinUi3 pesky persistent drop shadow

[mayhemphone]

Hey all, not sure if I'm in the right place, hoping someone with some WinUi3 experience can help - I cant find documentation to help me on this.

I'm building an app that is react-native-windows (please don't close the window yet lol). It uses WinUI3 with win32. I've successfully made the windows layer transparent, so my html/css can be any shape i want, with transparency, etc. The problem i run into, is the pesky drop shadow around the windows app. I cannot for the life of me find the right place to turn that off. For all i know it's not possible, though that would be pretty frustrating. Anyone have any advice here?

Even if it's someone pointing me to a better place to ask?

Many thanks 🙏

[castorix]

On which OS ?
On Windows 10, I don't have shadow on Layered transparent windows.
For Windows 11, people told me that shadow was set/unset with DwmSetWindowAttribute and different values of DWM_WINDOW_CORNER_PREFERENCE