When you declare the HECRASController as public, RAS will remain open as an application outside the scope of a given procedure-QuitRAS only hides it. If you want RAS to close at the conclusion of the procedure, you have to declare the HECRASController within the scope of that procedure. Then at the end of the procedure, RAS will close as an application.
It’s possible that you could find some third-party code to manually close RAS as an application. I suggest Googling “vba close an application” and see if you can find a way. If you do, please share with the group.
Thanks-
Chris