Usually when you open a container, your inventory, or many other screens, the mouse turns to a pointer and moving it has no effect on your character.
Once you finish this, and return to the game, the mouse returns to a reticle and then moving the mouse will make your character return to moving.
Since patch, this doesn't work anymore. I look at a book or open inventory, and after closing the inventory, the mouse still remains as an arrow cursor.
if I type movement keys (WASD) then it returns to a reticle.
Is this some new setting? My wife's computer doesn't do this, just mine.