It sounds like you're describing what are called toasts (don't ask me why, but that's what these "slide in" messages from Windows 10 that are generally logged in the Action Center afterward are called). You get this quick alert tone, the thing slides in from the bottom right side of the screen, then pretty quickly disappears. I often can't get to them in time and I can see them slide in.
The good thing is that these do get logged in the Action Center and you can go through the list of toasts that have popped up recently that way. -- Brian
A great many people think they are thinking when they are merely rearranging their prejudices.
