If you mean you factory reset them, why?????

But if so, you now need to treat them as new devices and add them to your system. 
 

If you did something different, please clarify exactly what you did when “resetting the app and the speakers”. 

​@meo149,
If all speakers were factory reset in one fell swoop, then you need to create a brand new Sonos system household in which to hold those speakers - you cannot use the ‘existing’ Household. It’s a case of starting from scratch, but I too would ask why anyone would want to reset all their products, unless planning to sell/give away the whole lot?

Certainly resetting all Sonos devices would wipe any services and content from the controller app, which is just a window into the actual app running on the devices.