Microsoft have changed the default context menu in Windows 11 (https://blogs.windows.com/blog/2021/07/19/extending-the-context-menu-and-share-dialog-in-windows-11/) and therefore the "Edit with Notepad++" context menu entry is no longer present on the main menu and you need to go to the overflow.

It'd be nice to be able to get the context menu entry again. Unfortunately it looks like you need a packaged identity to use the Windows 11 menu so you'd need to deploy a manifest with the application, but I guess you have a signing key so it might not be that big an issue. Also maybe it's something to wait for closer to a final release as Microsoft could easily change things if enough people complain.