During a round in Quick Play OW2 I tried to play Junkrat and discivered my Primary Fire was not working. I swapped between heroes and learned serveral other heores primary fires were not working. I have not touched my hero setting or changed any controls for months and even then when looking through settings all Primary Fires are bound and set.
Did you try different heroes in practice range? Are your primary fire buttons the same for every hero? Can you try switch temporarily to another binding to see if that helps? You know, to rule out problems with your keyboard or controller.