Can someone confirm if a username of admin and a blank password is the correct default username and password for the RB4011 GS+RM . I cannot access the router via the browser. Winbox sees the router but says the password is incorrect. I have tried to factory reset the router however I have no way to confirm that the reset is actually successfully completing

Username is admin, but Mikrotik started randomizing the password for their newer products like the RB4011, so you must check the sticker in the box, on the router, on the box, wherever there is one. Worst case netinstall or flashfig