Stateless form button 'on click' won't update record (or do anything at all!)

Stateless form button 'on click' won't update record (or do anything at all!)

I'm going crazy over this one since I can't figure out what's wrong.

I have a stateless form that fetches data from an existing form in order to update a specific record. I know that the code works because when I use it on another field (on input) it does updates the records, but the same code when used under on click on a stateless form button I doesn't do anything. I tried an alert, or using openURL to open a new window, just to see if the onClick was doing anything but it doesn't seem to be.

This is the relevant part of the code:

fetchMe = Inventario [ID == input.ICCID];
fetchMe.Entregado_a = input.Distribuidor;
fetchMe.Punto_de_venta = input.Punto_de_venta;
fetchMe.Estado_SIM = "Entregado";